Judge CALABRESI concurs, and also files a separate concurring opinion. Judge WALKER concurs in part and dissents in part in a separate opinion.
Defendants Lynne Stewart, Mohammed Yousry, and Ahmed Abdel Sattar appeal from judgments of conviction of the United States District Court for the Southern District of New York (John G. Koeltl, Judge) for various crimes arising from their contacts with and behavior relating to government restrictions on communications and other contacts with Sheikh Omar Ahmad Ali Abdel Rahman. Rahman is serving a life sentence in a maximum security prison for terrorism-related crimes of seditious conspiracy, solicitation of murder, solicitation of an attack on American military installations, conspiracy to murder, and a conspiracy to bomb. He is subject to “Special Administrative Measures” (“SAMs”) restricting his ability to communicate with persons outside of the prison in which he is incarcerated so as to prevent him from continuing to lead terrorist organizations and their members. The government cross-appeals from the defendants’ sentences.
We would be remiss if we did not, at the outset, commend the district court for its thoroughness, thoughtfulness, and effectiveness in the conduct of these unusually lengthy, difficult, and sensitive proceedings. Much of what follows simply reports what it did and tracks what it said.
We affirm the judgments of conviction. We also affirm the sentences of Yousry and Sattar. We remand the case, however, with respect to the sentence of Stewart, and also with respect to the sentences of Yousry and Sattar in light of the resentencing of Stewart.
In particular, we affirm the judgments as to each defendant’s conviction of con*99spiring to defraud the United States, in violation of 18 U.S.C. § 371, by violating SAMs imposed upon Abdel Rahman. Contrary to the defendants’ arguments, the evidence is sufficient to sustain these convictions. Moreover, we reject both Stewart’s argument that, as a lawyer, she was not bound by the SAMs, and her belated argument collaterally attacking their constitutionality.
We affirm as to Sattar’s conviction of conspiring to murder persons in a foreign country in violation of 18 U.S.C. § 956, and his conviction of soliciting persons to commit crimes of violence — viz., murder and conspiracy to commit murder — in violation of 18 U.S.C. § 373. We conclude that the evidence is sufficient to sustain these convictions, especially in light of testimony establishing that Sattar attempted to undermine a unilateral cease-fire by an Egyptian terrorist organization and to draft a fatwa calling for, inter alia, the killing of “Jews and Crusaders.”
We affirm as to Stewart’s and Yousry’s convictions of providing and concealing material support to the conspiracy to murder persons in a foreign country in violation of 18 U.S.C. § 2339A and 18 U.S.C. § 2, and of conspiring to provide and conceal such support in violation of 18 U.S.C. § 371. We conclude that the charges were valid — that 18 U.S.C. § 2339A is neither unconstitutionally vague as applied nor a “logical absurdity,” as Stewart asserts— and that the evidence was sufficient to sustain the convictions. We also reject Stewart’s claims that her purported attempt to serve as a “zealous advocate” for her client provides her with immunity from the convictions.
Finally, we affirm Stewart’s convictions for knowingly and willfully making false statements in violation of 18 U.S.C. § 1001 when she affirmed that she intended to, and would, abide by the SAMs. In light of her repeated and flagrant violation of the SAMs, a reasonable factfinder could conclude that Stewart’s representations that she intended to and would abide by the SAMs were knowingly false when made.
We reject the remaining challenges to the convictions. We affirm the district court’s rejection of Sattar’s vindictive prosecution claim because there is insufficient evidence to support a finding that the government’s pre-trial decision to add new charges against Sattar amounted to an effort to punish him for exercising his constitutional rights. And, because Stewart’s conduct was materially different from, and more serious than, the conduct of other lawyers representing Abdel Rahman who may also have violated the SAMs, we affirm the district court’s rejection of Stewart’s claim that she was selectively prosecuted on account of her gender or political beliefs. We also conclude that the district court did not abuse its discretion in declining to sever the trial of Stewart and Yousry from that of Sattar in light of the general preference for joint trials, the specific charges at issue here, and the district court’s curative instructions. Nor did the district court abuse its discretion by empaneling an anonymous jury in light of the particular allegations of criminal wrongdoing at issue, involving the corruption of the judicial process, and the widespread publicity about the case. We find no fault with the district court’s resolution of allegations of juror impropriety. We also agree with the district court’s treatment of confidential information, including its denial of Stewart’s motion to suppress evidence obtained pursuant to the Foreign Intelligence Surveillance Act (“FISA”), its ex parte, in camera examination of FISA wiretap applications, and its rejection of Stewart’s more general challenges to the constitutionality of FISA. Finally, we find no fault with the district court’s treatment, *100in accordance with the Classified Information Procedures Act (“CIPA”), of Stewart’s motion to compel disclosure of information related to potential surveillance conducted by the National Security Agency.
We therefore affirm the convictions in their entirety.
We also affirm the sentences of Sattar and Yousry. We conclude that the district court committed neither procedural error in calculating the applicable Guidelines ranges, nor substantive error in varying from those ranges pursuant to its consideration of the factors set forth in 18 U.S.C. § 3553(a). We nonetheless remand their cases to the district court to allow it to reconsider their sentences should it choose to do so in light of the resentencing of Stewart.
We cannot affirm Stewart’s sentence on the basis of the record before us. Because the district court declined to find whether Stewart committed perjury at trial, we cannot conclude that the mitigating factors found to support her sentence can reasonably bear the weight assigned to them. This is so particularly in light of the seriousness of her criminal conduct, her responsibilities as a member of the bar, and her role as counsel for Abdel Rahman. We therefore remand the cause to the district court for further consideration of her sentence, in light of, among other things, the charges of perjury against her and of any other matter it deems necessary or advisable, and direct the court to revoke Stewart’s and Yousry’s bail pending appeal and to order them to surrender to the United States Marshal to begin serving their sentences forthwith.
BACKGROUND
The transcript of the trials in the cases on appeal runs in excess of thirteen thousand pages. The district court issued nine opinions and a wide variety of orders addressing issues presented during the course of the proceedings. See principally, United States v. Sattar, 272 F.Supp.2d 348 (S.D.N.Y.2003) (“Sattar I”); United States v. Sattar, No. 02 Cr. 395(JGK), 2003 WL 22137012, 2003 U.S. Dist. LEXIS 16164 (S.D.N.Y. Sept. 15, 2003) (“Sattar II”); United States v. Sattar, 314 F.Supp.2d 279 (S.D.N.Y.2004) (“Sattar III”); United States v. Sattar, 395 F.Supp.2d 66 (S.D.N.Y.2005) (“Sattar IV’); United States v. Sattar, 395 F.Supp.2d 79 (S.D.N.Y.2005) (“Sattar V”).1 The filings in this Court reflect the massiveness of the record.2 We therefore describe the proceedings in the district court and the relevant facts only in the detail we think necessary to explain our decision. In reviewing the conviction, we set forth the facts, as we must, in the light most favorable to the government. See United States v. Aleskerova, 300 F.3d 286, 292 (2d Cir. 2002).
*101 The SAMs
In October 1995, Sheikh Omar Ahmad Ali Abdel Rahman was convicted of a variety of terrorism-related crimes in the United States District Court for the Southern District of New York. According to the government’s evidence at his trial,
Abdel Rahman, a blind Islamic scholar and cleric, was the leader of [a] seditious conspiracy, the purpose of which was “jihad,” in the sense of a struggle against the enemies of Islam. Indicative of this purpose, in a speech to his followers Abdel Rahman instructed that they were to “do jihad with the sword, with the cannon, with the grenades, with the missile ... against God’s enemies.” Abdel Rahman’s role in the conspiracy was generally limited to overall supervision and direction of the membership, as he made efforts to remain a level above the details of individual operations. However, as a cleric and the group’s leader, Abdel Rahman was entitled to dispense fatwas, religious opinions on the holiness of an act, to members of the group sanctioning proposed courses of conduct and advising them whether the acts would be in furtherance of jihad.[3]
United States v. Rahman, 189 F.3d 88,104 (2d Cir.1999) (per curiam), cert. denied, 528 U.S. 1094, 120 S.Ct. 830, 145 L.Ed.2d 698 (2000) (citations omitted). The crimes of conviction included soliciting the murder of Egyptian President Hosni Mubarak while he was visiting New York City; attacking American military installations; conspiring to murder President Mubarak; conspiring to bomb the World Trade Center in 1993, which succeeded; conspiring subsequently to bomb various structures in New York City, including bridges, tunnels, and the federal building containing the New York office of the Federal Bureau of Investigation (“FBI”), which did not succeed; and conspiring to commit crimes of sedition. Id. at 103-04,107-11. For these crimes, Abdel Rahman was sentenced to be incarcerated for the remainder of his life. Id. at 148. Following his conviction and appeal therefrom, Abdel Rahman’s legal team focused on two goals: improving his conditions of confinement, and obtaining his transfer from prison in the United States to Egypt.
The government asserts that Abdel Rah-man was linked to various other acts of violence: He is said to be, or to have been, a spiritual leader of what the indictment in the instant prosecution refers to as “ ‘alGama’a al-Islamiyya,’ a/k/a ‘ax-Gama’at,’ a/k/a ‘Islamic Gama’at,’ a/k/a ‘Egyptian alGama’at al-Islamiyya’ ” (hereinafter, “alGama’a”), also referred to by the district court and the parties in English as the “Islamic Group” or “IG.” See Superseding Indictment ¶ 8. Al-Gama’a was designated a foreign terrorist organization (“FTO”) by the United States Secretary of State in 1997 pursuant to 8 U.S.C. § 1189, see Notices, Designation of Foreign Terrorist Organizations, Department of State, Office of the Coordinator for Counterterrorism, 62 Fed.Reg. 52650 (Oct. 8, 1997), was redesignated an FTO in 1999 and 2001, see Notices, Designation of Foreign Terrorist Organizations, Department of State, Office of the Coordinator for Counterterrorism, 64 Fed.Reg. 55112 (Oct. 8, 1999); Notices, Redesignation of Foreign Terrorist Organization, Department of State, Office of the Coordinator for Counterterrorism, 66 Fed. Reg. 51088 (Oct. 5, 2001), and remains so designated today, see Foreign Terrorist Organizations, Fact Sheet, Department of State, Office of the Coordinator for Coun*102terterrorism (Apr. 8, 2008), available at http://www.state.gOv/s/ct/rls/fs/08/103392. htm (last visited Mar. 28, 2009).
“Federal regulations provide that the Bureau of Prisons may implement SAMs, ‘[u]pon direction of the Attorney General,’ when ‘reasonably necessary to protect persons against the risk of death or serious bodily injury.’ 28 C.F.R. § 501.3(a).” In re Basciano, 542 F.3d 950, 954 (2d Cir.2008) (alteration in original), cert. denied, — U.S. ——, 129 S.Ct. 1401, 173 L.Ed.2d 596 (2009). The Bureau of Prisons, following Abdel Rahman’s remand to its custody in August 1997, imposed severely restrictive SAMs upon him. They were designed to prevent him from directing or facilitating yet more violent acts of terrorism from his prison cell. The SAMs have been renewed, and sometimes modified, every 120 days since they were first imposed.
The May 11, 1998, SAMs applicable to Abdel Rahman “prohibited [him] from having contact with ... others (except as noted in this document) that could foreseeably result in [his] communicating information (sending or receiving) that could circumvent the SAM intent of significantly limiting [his] ability to communicate (send or receive) terrorist information.” SAMs of May 11, 1998, ¶ 3. To enforce this general prohibition, the measures regulated Abdel Rahman’s telephone contacts, id. ¶ 4, his mail, id. ¶ 5, and his visitors’ visits, id. ¶ 6. The measures limited his telephone contacts solely to his attorneys of record and his wife, id. ¶ 4(a), and prevented matters discussed in those calls from being “divulged in any manner to any third party,” id. ¶ 4(e)(i). The measures required the screening of all his outgoing and incoming non-legal mail, id. ¶ 5, and prohibited him from “talking] with, or otherwise communicat[ing] with, any representative of the news media,” including “through [his] attorney(s)/staff, or otherwise,” id. ¶ 8. The measures also provided for the monitoring of all non-legal visits. Id. ¶ 6. On the condition that his attorneys would not divulge any information to third parties, Abdel Rahman was permitted to communicate with his legal team by telephone, id. ¶¶ 4(a) & 4(d), mail, id. ¶ 5(a), and in person, id. ¶ 6, with fewer restrictions than with other persons. Members of this legal team included lawyers Ramsey Clark, Abdeen Jabara, Lawrence Schilling, and defendant Lynne Stewart.
Subsequent versions of the SAMs retained similar prohibitions and screening mechanisms including the prohibition against communications with the news media. See, e.g., SAMs of Apr. 7, 1999, ¶ 9; SAMs of Dec. 10, 1999, ¶ 9. They retained similar provisions regarding legal communications, and incorporated provisions requiring Abdel Rahman’s attorneys to sign affirmations acknowledging their receipt of the version of the SAMs in effect. See, e.g., SAMs of Apr. 7, 1999, ¶ 4; SAMs of Dec. 10, 1999, ¶ 4. By virtue of those affirmations, counsel agreed to abide by the terms of SAMs then in effect. See, e.g., Unsigned Affirmation of Abdeen Jabara, Apr. 2000; Unsigned Affirmation of Ramsey Clark, Apr. 2000; Affirmation of Ramsey Clark, Jan. 10, 2001; Affirmation of Abdeen Jabara, Jan. 10, 2001; Affirmation of Ramsey Clark, Apr. 24,1997.
Stewart repeatedly executed such statements. On May 1, 1998, she signed a document entitled “Attorney Affirmation,” in which she affirmed, under penalty of perjury, the truth of specified statements regarding the then-applicable SAMs: that she had read the May 11, 1998, version of the SAMs; that she “understood] the restrictions contained in that document and agree[d] to abide by its terms”; that during her visits to Abdel Rahman she would “employ only cleared translators/interpret*103ers and [would] not leave [any] translator/interpreter alone with inmate Abdel Rahman”; and that she would “only be accompanied by translators for the purpose of communicating with inmate Abdel Rahman concerning legal matters.” Affirmation of Lynne Stewart, May 1, 1998. Stewart also affirmed that neither she nor any member of her office would “forward any mail received from inmate Abdel Rah-man to a third person” nor would she “use [her] meetings, correspondence or phone calls with Abdel Rahman to pass messages between third parties (including, but not limited to, the media) and Abdel Rahman.” Id. On May 16, 2000, and again on May 7, 2001, Stewart signed similar affirmations under penalty of perjury, again affirming that she had read the most recent versions of the SAMs, and that she would not use her contact with Abdel Rahman to pass messages between him and third parties, including members of the media. Affirmation of Lynne Stewart, May 16, 2000; Affirmation of Lynne Stewart, May 7, 2001.
Defendant Mohammed Yousry, a middle-aged New York University graduate student who served as one of the legal team’s translators had also been, in that capacity, a member of Abdel Rahman’s trial team. As a translator, Yousry was permitted to read to Abdel Rahman, who is blind, and to take dictation from him.
Various members of the team, including Stewart and Yousry, also maintained contact with defendant Ahmed Abdel Sattar, who had served as a paralegal during Abdel Rahman’s trial. The evidence established that Sattar was in continual contact with various members of al-Gama’a abroad. See, e.g., Transcript of Conversation between Ahmed Abdel Sattar and Rifa’i Ahmad Taha Musa, May 9, 2000.
The Visits to Abdel Rahman
Sometime in 1997, more than three years after Abdel Rahman was taken into federal custody, a faction of al-Gama’a declared a unilateral “cease-fire,” i.e., a halting of violent operations, in Egypt. When the cease-fire was first announced, Abdel Rahman was understood to support it.
In November 1997, despite the ceasefire, a group associated with al-Gama’a attacked, killed, and mutilated the bodies of more than sixty tourists, guides, and guards at the Hatshepsut Temple in Lux- or, Egypt. Rifa’i Taha Musa (“Taha”) — a military leader of al-Gama’a, a follower of Abdel Rahman, and an unindicted co-conspirator herein — was involved in the incident.4 Alaa Abdul Raziq Atia (“Atia”), later a leader of al-Gama’a’s military wing in Egypt, was also involved in the killings. Al-Gama’a later claimed responsibility for the attack and demanded Abdel Rahman’s release from prison in the United States.
In January 1998, Abdel Rahman was assigned by the Bureau of Prisons to the Federal Medical Center in Rochester, Minnesota (“FMC Rochester”). In March 1999, Stewart and Yousry visited him there. Prior to the visit, Stewart signed and delivered to the United States Attorney’s Office for the Southern District of New York a document in which she affirmed, under penalty of perjury, that she would abide by the SAMs imposed by the Bureau of Prisons on Abdel Rahman.
At about this time, defendant Sattar was in contact with members of al-Gama’a, who were divided over their support for what remained of the cease-fire. Pro-cease-fire and anti-cease-fire factions developed, and members of the organization wanted Abdel Rahman to take a position on the matter. *104To that end, several wrote messages addressed to Abdel Rahman, which they sent to Sattar for delivery to Abdel Rahman. Sattar gave the messages to Stewart and Yousry, who surreptitiously brought the messages with them to Abdel Rahman during a subsequent visit in May 2000.
Yousry read the messages to Abdel Rahman during the visit, and Abdel Rah-man dictated to Yousry responses to some of them. Yousry and Stewart then smuggled the responses out of FMC Rochester among their legal papers, and sent them to Sattar. As directed by Abdel Rahman, Sattar informed various members of alGama’a that Abdel Rahman was willing to reconsider the effectiveness of the ceasefire and had rejected the associated idea that al-Gama’a should form a political party in Egypt.
News of Abdel Rahman’s purported position spread. But some members of the media in the Middle East expressed skepticism about the veracity of Sattar’s representations, questioning whether they in fact came from Abdel Rahman or whether Sattar had fabricated them himself. To refute those reports, Sattar and Yousry asked one of Abdel Rahman’s lawyers, former United States Attorney General Ramsey Clark, to tell a reporter for an Arabic-language newspaper that Abdel Rahman opposed al-Gama’a’s formation of a political party. Clark, they thought, would be perceived as more authoritative than Sat-tar. Clark eventually agreed to talk to the reporter. He told the reporter that “[t]he Sheikh has said he believes that the formation of a new political party to engage in politics in Egypt at this time is ... not correct and should not be done.” Transcript of Conversation between Ahmed Abdel Sattar, Mohammed Yousry, Ramsey Clark, and Muhammad Al-Shafi’i, Nov. 5, 1999, at 15.
In September 1999, Farid Kidwani, the then-leader of al-Gama’a’s military wing, was killed along with three other members of the group in a shootout with Egyptian police. Kidwani’s death precipitated further tension and debate within al-Gama’a regarding the advisability and efficacy of the cease-fire.
Taha sent another message to Sattar to be relayed to Abdel Rahman urging Abdel Rahman to support the termination of the cease-fire and noting that Taha and his associates needed a “powerful word” from Abdel Rahman to achieve this goal. Taha told Sattar that such support from Abdel Rahman would “strengthen me among the brothers.” Sattar agreed to send the message to Abdel Rahman and prepared a letter to Abdel Rahman for that purpose. In mid-September 1999, Clark and Yousry surreptitiously took the letter, along with newspaper articles relating to the killing of Kidwani in Egypt, with them during a visit to Abdel Rahman in FMC Rochester. Yousry read the letter and newspaper clippings aloud to Abdel Rahman. From these documents, Abdel Rahman first learned of Kidwani’s death.
Abdel Rahman dictated a letter to Yousry in response.
To those against whom war is made, permission is given to fight, because they are wronged (oppressed) — and verily God is most powerful for their aid----The latest thing published in the newspapers was about the Egyptian regime’s killing of four members of the Group. This is ... enough proof that the Egyptian regime does not have the intention to interact with this peaceful Initiative [i.e., the cease-fire] which aims at unification. I therefore demand that my brothers, the sons of [al-Gama’a] do a comprehensive review of the Initiative and its results. I also demand that they consider themselves absolved from it.
*105Transcript of Conversation between Ahmed Abdel Sattar and Rifa’i Ahmad Taha Musa, Sep. 20, 1999, at 6-7 (emphasis omitted, parenthetical in original). Sat-tar expected Clark to make a public statement to similar effect, but Clark declined to do so.
On February 18 and 19, 2000, Yousry and Abdeen Jabara, an Arabic-speaking lawyer and member of Abdel Rahman’s legal team, visited Abdel Rahman at FMC Rochester. They brought with them another letter which included another message from Taha, again asking for Abdel Rahman’s support for ending the ceasefire. But Jabara would not permit Abdel Rahman to dictate a letter to Yousry in response. And, notwithstanding pressure from Sattar and Taha, Jabara, like Clark before him, refused to issue any public statement regarding Abdel Rahman’s position on the matter.
On May 16, 2000, defendant Stewart signed another affirmation that she and her staff would abide by the SAMs. She did not submit that affirmation to the United States Attorney’s Office until May 26.
On May 18, 2000, Stewart met with Sat-tar, who gave her more letters for Abdel Rahman, including another message from Taha yet again seeking Abdel Rahman’s approval of an end to the cease-fire. Taha asked Abdel Rahman to take a “more forceful position” regarding the end of the cease-fire and to “dictate some points we can announce in a press conference with Lynne.” Transcript of Second Audiovisual Recording involving Omar Abdel Rahman, Mohammed Yousry, Lynne Stewart, and others, May 19, 2000, (“Video Tr. May 19, 2000, Tape 2”),5 at 36.
On May 19 and 20, 2000, Stewart and Yousry visited Abdel Rahman, taking Sat-tar’s most recent letters with them, including the letter containing the message from Taha. Unbeknownst to them, the government, pursuant to a warrant, videotaped the meetings. Yousry told Abdel Rahman that Abu Sayyaf — an Islamic terrorist group in the Philippines- — -had taken hostages to be used in bargaining for the release of Abdel Rahman and others. When Yousry explained to Stewart that he was “telling the Sheikh about the Abu Sayyaf group in the Philippines” and how “they took hostages,” Stewart replied, “Good for them.” Transcript of First Audiovisual Recording involving Omar Abdel Rahman, Mohammed Yousry, and Lynne Stewart, May 19, 2000, at 27.
From the beginning of the visit, Stewart was aware of the prison guards’ presence. For example, she asked Yousry, “Do they usually sit like this and watch us?” Id. at 10. And during this meeting, Stewart and Yousry took overt steps to ensure that the nature of their communication with Abdel Rahman would be concealed from the prison guards. As she suggested to Yousry, they “should give them [i.e., the guards] something to watch.” Id. at 11. When the guards were standing close to the window of the conference room in which Abdel Rahman, Stewart, and Yousry, were meeting Yousry told Stewart to “look at me and talk a little bit because they are watching us closely.” Id. at 51. While Yousry read the message to Abdel Rahman, Stewart uttered a meaningless series of phrases to Yousry so that it would appear to an observer as though she was taking part in a three-way conversation: “I am talking to you about ... him going to have a, uh, *106chocolate eh ... heart attack here.... Why don’t you stop a minute now. And (UI)6 say to him that, you know, ‘You understood what we are saying, (UI).’ ” Id. As Stewart spoke, Yousry said to Abdel Rahman, “I don’t know, Sir, they are standing very close by the glass.... Lynne says, (UI) when they look, you look at me a little, talk, then look at the Sheikh.” Id.
Stewart continued to talk while Yousry read aloud Taha’s statement in Sattar’s letter. Yousry explained to Abdel Rah-man that “Lynne just says anything, [laughing] (UI) Sir.” Id. at 52 (bracketed material in original). Stewart remarked, “I can get an academy award for it.” Id.
Stewart and Yousry then had this exchange:
YOUSRY: ... Lynne, I think you should talk to him because they are looking at me.
STEWART: (UI) there (UI), they, uh, (UI) ... [she taps Yousry’s pad with her pen]7 uhm, if he finds out what this is, then we’re ... [Laughs.]
YOUSRY: [Laughs] In trouble. STEWART: [Laughing] Yeah, that’s right.
Video Tr. May 19, 2000, Tape 2, at 29 (brackets in original).
Stewart and Yousry also took evasive action when a guard appeared to take interest in their conversation. At one point, while Yousry was conversing with Abdel Rahman, Stewart touched Yousry’s hand and said “Why don’t you stop there and we’ll talk a minute urn, the, uh.... Ahmed’s youngest son needs glasses, did you know that?” Id. at 30. Yousry then explained to Abdel Rahman, “Lynne says, stop a little because they are by the glass.” Id. Not long afterwards, Stewart tapped with the pen on the paper in front of Yousry and told him to “continue reading this ‘cause this is setting up the organizational system around his conditions.’ ” Id. Yousry continued reading. Stewart then made a series of statements unrelated to the substance of the conversation between Yousry and Abdel Rahman. Yousry kept Abdel Rahman informed of what Yousry and Stewart were doing, noting that “Lynne continues to eh, she’s watching them, she’s watching them,” to which Abdel Rahman replied, “[v]ery good, very good.” Id. at 33. After Yousry finished reading Taha’s message to Abdel Rahman, he returned it to a notebook that he had brought with him and with which he left.
On the second day of the same visit, Abdel Rahman dictated to Yousry, among other things, a letter to an al-Gama’a lawyer who favored the cease-fire, asking him to allow others in al-Gama’a to criticize it, and another to Taha asking him to “escalate the language” of criticism of the ceasefire. Video Tr. May 20, 2000, Tape 2, at 32.
Meanwhile, Stewart and Yousry continued to engage in what Stewart later called “[c]overing noises,” Video Tr. July 13, 2001, Tape 2, at 12, and other tactics designed to obscure the nature of what they were doing. After one such incident, Yousry explained to Abdel Rahman, “[S]he just has to say that in order to break the ... The people are looking.” Video Tr. May 20, 2000, Tape 1, at 14. Stewart told Yousry, “I am making allowances for them looking in at us and seeing me never speaking and writing away here while you talk Arabic.” Id. at 17. She then directed *107Yousry to “talk back to me now, because otherwise it doesn’t make any sense.... So say something in English....” Id. As Yousry explained to Abdel Rahman, “We are now acting, I talk to her in Arabic, and she responds in English, and they don’t understand what is going on.” Video Tr. May 20, 2000, Tape 2, at 38.
At the end of the visit, Stewart and Yousry took the Yousry-transcribed responses from Abdel Rahman with them from the prison, and later gave them to Sattar. Sattar then passed them along to Taha and another member of al-Gama’a. Sattar also spoke to various members of al-Gama’a, informing them that Abdel Rahman would have “no objection” to a return to violence. Transcript of Audio Recording of Ahmed Abdel Sattar, Rifa’i Ahmad Taha Musa, and Salah Hashim, May 29, 2000, at 3.
At about this time, Sattar told members of al-Gama’a that Stewart would be making a public statement about Abdel Rah-man’s views on the cease-fire. Sattar and Stewart first discussed what Stewart would say to the press. Then, on June 13, 2000, Sattar and Stewart spoke to Esmat Salaheddin, a Reuters reporter based in Cairo. Stewart told Salaheddin that Abdel Rahman “is withdrawing his support for the ceasefire that currently exists.” Trial Transcript (“Trial Tr.”) at 5574, 5617, testimony of Salaheddin. She explained that Abdel Rahman had made the statement from prison two weeks before.
The next day, other Middle Eastern press outlets carried the news that Abdel Rahman had withdrawn his support for the cease-fire. Many noted that for the ceasefire to hold, Abdel Rahman’s support was essential.
On June 20, 2000, Stewart participated in a telephone conference with Abdel Rah-man. She then sent another statement on Abdel Rahman’s behalf via facsimile to Salaheddin, the Reuters reporter in Cairo. The telecopy said, “Everything said in the previous statements is correct” and quoted Abdel Rahman as saying, “I do withdraw my support to the [cease-fire] initiative.” Statement for Release, Abdel Rahman, June 20, 2000. Following Stewart’s statements on Abdel Rahman’s behalf, several members of al-Gama’a began preparations to engage anew in acts of violence.
On October 4, 2000, Sattar and Taha completed a fatwa on Abdel Rahman’s behalf, imitating his style, “mandating the killing of the Israelis everywhere” and “the killing [of] the Jews wherever they are (UI) and wherever they are found.” Transcript of Audio Recording of Ahmed Abdel Sattar and Yassir Al-Sirri Oct. 4, 2000, (“Audio Tr. Oct. 4”) at 13-16.8 Sat-*108tar sent the fatwa to, among others, Atia, who had in the meantime become the military leader of al-Gama’a. Upon receiving the message, Atia began preparing for an attack. But, on October 19, 2000, before Atia could act, the Egyptian authorities raided his hideout, killing him and killing or arresting other al-Gama’a members.
On July 13 and 14, 2001, Stewart again paid a visit to Abdel Rahman at FMC Rochester, having signed a revised affirmation agreeing to abide by the SAMs and having sent the affirmation by facsimile to the United States Attorney’s Office for the Southern District of New York on May 7, 2001. Stewart again, with Yousry’s assistance and contrary to provisions of the SAMs, surreptitiously brought messages to and from Abdel Rahman.
Procedural History
On April 8, 2002, the defendants were indicted in connection with these and related acts; a superseding indictment was filed on November 19, 2003. On February 10, 2005, a jury found the defendants guilty on all counts in the superseding indictment. Specifically, all three defendants were convicted of conspiring to defraud the United States in violation of 18 U.S.C. § 371 (Count One) by violating SAMs imposed upon Abdel Rahman, and various related offenses. Sattar was convicted of conspiring with Taha, Abdel Rah-man, and others to murder persons in a foreign country in violation of 18 U.S.C. § 956 (Count Two), and with soliciting persons to commit crimes of violence — murder and conspiracy to commit murder — in violation of 18 U.S.C. § 373 (Count Three). Stewart and Yousry were convicted of providing and concealing material support to the Count-Two conspiracy, in violation of 18 U.S.C. § 2339A and 18 U.S.C. § 2 (Count Five), and with conspiracy to provide and conceal such support, in violation of 18 U.S.C. § 371 (Count Four). Stewart was also convicted of making false statements in violation of 18 U.S.C. § 1001 (Counts Six and Seven).
On October 16, 2006, following the denial of the defendants’ motions for a judgment of acquittal and other relief, the district court sentenced the defendants. See Sentencing Transcript of Oct. 16, 2006 (“Sent’g Tr.”). Sattar was sentenced to a 288-month term of incarceration to be followed by a five-year term of supervised release and a $300 special assessment; Stewart was sentenced to a 28-month term of incarceration to be followed by a two-year term of supervised release and a $500 special assessment; and Yousry was sentenced to a 20-month term of incarceration to be followed by a two-year term of supervised release and a $300 special assessment. Sattar is currently serving his sentence; Stewart and Yousry are free on bail pending appeal.9
All three defendants appeal, challenging the validity of their convictions on a variety of grounds. The government challenges the reasonableness of the sentences on cross-appeal.
*109DISCUSSION
I. Standard of Review
We review de novo the district court’s legal conclusions, including those interpreting and determining the constitutionality of a statute. United States v. Awadallah, 349 F.3d 42, 51 (2d Cir.2003), cert. denied, 543 U.S. 1056, 125 S.Ct. 861, 160 L.Ed.2d 781 (2005). We also review de novo a district court’s denial of a motion pursuant to Federal Rule of Criminal Procedure 29 for a judgment of acquittal on the ground that the evidence was insufficient to sustain the conviction. United States v. Florez, 447 F.3d 145, 154 (2d Cir.), cert. denied, 549 U.S. 1040, 127 S.Ct. 600, 166 L.Ed.2d 445 (2006). Because the jury verdict will be upheld against a sufficiency challenge “if we find that ‘any rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt,’ ” United States v. Autuori, 212 F.3d 105, 114 (2d Cir.2000) (quoting Jackson v. Virginia, 443 U.S. 307, 319, 99 S.Ct. 2781, 61 L.Ed.2d 560 (1979) (emphasis in Jackson)), a convicted defendant making such a claim “bears a very heavy burden,” United States v. Desena, 287 F.3d 170, 177 (2d Cir.2002). We are required to evaluate “all of the evidence in the light most favorable to the government.” United States v. Aleskerova, 300 F.3d 286, 292 (2d Cir.2002).
II. Count One
Each defendant asserts that the evidence admitted at trial was insufficient to support his or her conviction under 18 U.S.C. § 371 for defrauding the United States and obstructing the Department of Justice and the Bureau of Prisons in the administration and enforcement of the SAMs in force with respect to Abdel Rah-man. Stewart also argues that the SAMs do not apply to lawyers, and that the district court improperly prevented her from challenging the underlying validity of the SAMs.
A. Sufficiency of the Evidence
In order to establish a conspiracy-to-defraud offense under 18 U.S.C. § 371 as charged in Count One of the indictment, a reasonable jury must have been able to conclude beyond a reasonable doubt “(1) [that the defendants] entered into an agreement (2) to obstruct a lawful function of the government [in this case, the administration and enforcement of the SAMs] (3) by deceitful or dishonest means and (4) at least one overt act in furtherance of the conspiracy.” United States v. Ballistrea, 101 F.3d 827, 832 (2d Cir.1996), cert. denied, 520 U.S. 1150, 117 S.Ct. 1327, 137 L.Ed.2d 488 (1997) (citation and internal quotation marks omitted). “ ‘Both the existence of a conspiracy and a given defendant’s participation in it with the requisite knowledge and criminal intent may be established through circumstantial evidence.’ ” United States v. Huezo, 546 F.3d 174, 180 (2d Cir.2008) (quoting United States v. Stewart, 485 F.3d 666, 671 (2d Cir.2007)) (alteration omitted).
1. Evidence as to Stewart. Stewart argues that her defiance of the SAMs was open, not deceitful. One aspect of her defiance was undoubtedly public — the conveyance of Abdel Rahman’s statements regarding the cease-fire and related matters to the Reuters journalist. But we agree with the district court that “[a] reasonable jury could certainly [have found] that Stewart gained access to Abdel Rahman [and thereby the information that she conveyed to the journalist] by deceit and dishonest means.” Sattar V, 395 F.Supp.2d at 89. “Without [Stewart’s] agreement to abide by the SAMs and the other representations contained in her affirmations, she knew that she would not have been allowed to visit Abdel Rahman,” id.; see *110also id. at 84-89, and therefore would not later have been able to defy the regulations openly by publicizing messages on his behalf.
Stewart insists that she acted with the intent, not to defraud the government, but to “zealously” represent her client.10 But the jury had a reasonable basis on which to disbelieve this, and to “disbelieve that zealous representation included filing false affirmations, hiding from prison guards the delivery of messages to Abdel Rah-man, and the dissemination of responses by him that were obtained through dishonesty.” Id. at 90. Moreover, even if Stewart acted with an intent to represent her client zealously, a rational jury could nonetheless have concluded that Stewart simultaneously acted with an intent to defraud the government. A genuinely held intent to represent a client “zealously” is not necessarily inconsistent with criminal intent.
2. Evidence as to Yousry. Yousry argues that, as a translator who was taking direction from others, he did only what he was told to do and acted in good-faith reliance on the guidance and conduct of the members of the bar for whom he worked. Based on the evidence admitted at trial, however, a rational jury could have found that Yousry knew of and understood the terms of the SAMs.
Yousry had in his possession the December 1999 version of the SAMs as well as a copy of the underlying regulations. That version of the SAMs provided that Abdel Rahman’s legal team could pass along to him “only inmate case-related correspondence,” and set forth a process for screening all non-legal mail. SAMs of Dec. 10, 1999, ¶ 7. The SAMs in Yousry’s possession also specifically prohibited Abdel Rah-man’s communication with news media “in person, by telephone, by furnishing a recorded message, through the mails, through his attorney(s), or otherwise.” Id. ¶ 9. Yousry himself acknowledged that members of the legal team were not “to disclose any portion of their conversation with the Sheik to the media.” Excerpts from Draft of Dissertation of Mohammed Yousry at 29. Yousry also knew that Clark and Jabara had refused to relay messages from Abdel Rahman.
From this evidence, a reasonable factfinder could conclude beyond a reasonable doubt that Yousry knew that his assistance, by providing translation services, in facilitating Abdel Rahman’s continued contact with members of al-Gama’a violated the SAMs. Moreover, as with Stewart, Yousry’s deceptive and evasive conduct during the course of his visits to Abdel Rahman undercuts his claim of good faith.
Yousry argues that the evidence established, at most, that he intended to violate the SAMs, not that he knew that doing so might constitute a crime. But even if he misunderstood the law in that respect, such a mistake provides no defense to a charge of criminal misbehavior. See Cheek v. United States, 498 U.S. 192, 199, 111 S.Ct. 604, 112 L.Ed.2d 617 (1991). The fact that Yousry was aware that his acts, *111in knowing violation of the SAMs, would defraud the government is sufficient to sustain the conviction. The government need not also prove that he knew that there was a criminal statute — 18 U.S.C. § 371 — that criminalized such behavior. “The general rule that ignorance of the law or a mistake of law is no defense to criminal prosecution is deeply rooted in the American legal system.” Cheek, 498 U.S. at 199, 111 S.Ct. 604.
B. Propriety of the SAMs
1. Stewart’s Argument. Stewart contends that the district court erred by preventing her from challenging the validity of the SAMs as part of her defense. She sought to argue that the Attorney General has no authority to have lawyers held criminally liable for violating the SAMs and that the SAMs are unconstitutionally vague as applied to her. Under Dennis v. United States, 384 U.S. 855, 86 S.Ct. 1840, 16 L.Ed.2d 973 (1966), however, Stewart’s strategy of collaterally attacking the validity of the SAMs is futile.
As the Supreme Court recognized in Dennis, there are “appropriate and inappropriate ways to challenge acts of government thought to be unconstitutional.” Id. at 867, 86 S.Ct. 1840. There is “no reason for [federal courts] to consider the constitutionality of a statute at the behest of petitioners who have been indicted for conspiracy by means of falsehood and deceit to circumvent the law which they now seek to challenge.” Id. at 866, 86 S.Ct. 1840. Stewart, like the defendants in Dennis, was indicted for engaging in a “voluntary, deliberate and calculated course of fraud and deceit.” Id. at 867, 86 S.Ct. 1840. This is a “prosecution directed at [Stewart’s] fraud[,] not an action to enforce the [law] claimed to be unconstitutional.” Id.11
The result may be different where the constitutionality of a law is “challenged by those who of necessity violate its provisions and seek relief in the courts,” id. at 865, 86 S.Ct. 1840, or where the governmental action at issue was taken with no “colorable authority,” United States v. Barra, 149 F.2d 489, 490 (2d Cir.1945).12 But, as with Dennis, “[t]his is not such a case.” 384 U.S. at 865, 86 S.Ct. 1840.
We have no basis upon which to entertain a doubt as to the authority of the Attorney General of the United States to *112ensure that reasonable measures are designed and implemented in an attempt to prevent imprisoned criminals who are considered dangerous despite their incarceration from engaging in or facilitating further acts of criminality from their prison cells. See 28 C.F.R. § 501.3(a) (setting forth the boundaries of that authority). Nor have we any reason to doubt the Attorney General’s conclusion that Abdel Rahman fits within that category of prisoner. He has demonstrated his willingness to engage in violent criminality not by acting violently himself, but by ordering, encouraging, and conspiring with others who would actually shed the blood. The likelihood that he would continue to order, direct, or encourage such acts from prison, if he could, was plain, and his incapacitation reasonably required not just his physical immobility, but also his virtual silence visa-vis the world at large.
Stewart might have effectively challenged the SAMs by refusing to sign the affirmations in which she said she would abide by them. She might then have invoked the jurisdiction of the courts by bringing suit on Abdel Rahman’s or her own behalf to challenge their validity. She might have argued — as she forcefully does here — that the SAMs interfered with her capacity to effectively represent Rahman. But she did not. Instead, she signed the affirmations. Having chosen that path, she cannot be heard to attack the validity of those measures when called to account for violating them, especially where, as here, her fraudulent and deceptive conduct endangered people’s lives.
The district court did not err in preventing Stewart from challenging the validity of the SAMs as part of her defense, and the jury acted within its province when it found that Stewart intentionally and fraudulently subverted them.
£ Sattar’s Related Arguments on Appeal. Sattar relies on Stewart’s and Yousry’s arguments with respect to Count One. For the reasons set forth above addressing those arguments, we conclude that they are also unpersuasive as applied to him.
III. Counts Two and Three
Only Sattar was charged in Counts Two and Three of the superseding indictment. He does not challenge the sufficiency of the evidence supporting his Count Two conviction for conspiring with Abdel Rah-man, Taha, and others to murder persons in a foreign country, in violation of 18 U.S.C. § 956.13 Instead, he asserts that the district court should have dismissed this count on the grounds of vindictive prosecution. Similarly, Sattar does not challenge his conviction on Count Three for soliciting persons to engage in crimes of violence — murder and conspiracy to commit murder — in violation of 18 U.S.C. § 373.14 He argues instead that he was denied a fair trial. These arguments are addressed below in the context of the defendants’ more general challenges to the probity of the proceedings.
IV. Counts Four and Five
Stewart and Yousry challenge their Count Five convictions for violating 18 U.S.C. § 2339A and 18 U.S.C. § 2 by providing and concealing material support for the Count-Two conspiracy for which Sat-tar was convicted and their Count Four convictions for conspiracy to provide and conceal such support, in violation of 18 U.S.C. § 371. They argue that the evi*113dence was insufficient to support their conviction on either count, and contend that their conduct was constitutionally protected in any event.
A. History of the Charges
By way of background, the initial indictment charged all three defendants with violating 18 U.S.C. § 2339B.15 The defendants argued before the district court that “18 U.S.C. § 2339B is unconstitutionally vague ... with regard to the statute’s prohibition on providing material support or resources in the form of communications equipment and personnel.” Sattar I, 272 F.Supp.2d at 356 (internal quotation marks omitted). The district court agreed, and therefore dismissed those charges. Id. at 361.16
The government then filed a superseding indictment alleging that by essentially the same course of conduct, i.e., coordinating the surreptitious passage of al-Gama’a messages to and from Abdel Rahman, Stewart and Yousry violated 18 U.S.C. § 2339A.17 The relevant version of section 2339A, entitled “Providing material support to terrorists,” provided in relevant part:
Whoever, within the United States, provides material support or resources or conceals or disguises the nature, location, source, or ownership of material support or resources, knowing or intending that they are to be used in preparation for, or in carrying out, a violation of [various enumerated statutes related to terrorism] or in preparation for, or in carrying out, the concealment of an escape from the commission of any such violation, or attempts or conspires to do such an act, shall be [subject to criminal punishment],
18 U.S.C. § 2339A(a) (2000). For purposes of both sections 2339A and 2339B, “material support or resources” may be provided in the form of:
currency or other financial securities, financial services, lodging, training, safehouses, false documentation or identification, communications equipment, facilities, weapons, lethal substances, explosives, personnel, transportation, and other physical assets, except medicine or religious materials.
18 U.S.C. § 2339A(b)(l) (2000); see also id. § 2339B (g)(4) (2000) (“[T]he term ‘material support or resources’ has the same meaning given that term in section 2339A....”). Section 2339A, however, in contrast to section 2339B, does not penalize the provision of material support without regard to what the support is for. Section 2339A requires instead that the defendant provide support or resources with the knowledge or intent that such resources be used to commit specific violent crimes.18
*114The government charged that the defendants provided “material support or resources” in the form of “personnel”— namely, Abdel Rahman — to the Counts Two conspiracy, knowing or intending that Abdel Rahman, as an active co-conspirator, would help commit crimes. See Sattar III, 314 F.Supp.2d at 296. The government further asserted that Stewart and Yousry “concealed] and disguise[d] the nature, location, and source” of their material support by means of the defendants’ covert conduct disguising Abdel Rahman’s participation as a co-conspirator. See id. The government had initially argued that Stewart and Yousry could be convicted for providing themselves as “personnel” to a foreign terrorist organization and by providing communications equipment to the conspiracy. After the dismissal of the section 2339B charges and following the filing of the superseding indictment, however, the government abandoned those contentions. See id.
As an initial matter, Stewart and Yousry challenge the sufficiency of the evidence supporting their convictions on this count. They also argue that the district court erroneously instructed the jury on the elements of a violation of section 2339A. In addition, they raise more general challenges to the statute, arguing that section 2339A does not criminalize the behavior alleged in the indictment, that the provision is unconstitutional as a multi-level inchoate offense, and that the statute is unconstitutionally vague as applied to them. We examine their arguments in the context of the statutory elements of the crime, addressing first the sufficiency arguments.
B. Elements of Section 2339A
1. Proof of the Underlying Conspiracy to Kill Persons Abroad.19 There was sufficient evidence of the existence of the predicate crime — the Count-Two conspiracy to kill or kidnap — for which Sattar was convicted. Indeed Sattar, the only defendant charged with and convicted of participating in the Count-Two conspiracy, does not challenge the sufficiency of the evidence as to this count.
The government offered evidence that Sattar and Taha composed a fatwa in Abdel Rahman’s name calling for “the killing [of] the Jews wherever they are (UI) and wherever they are found.” Audio Tr. Oct. 4, at 15. It also offered proof that this fatwa was communicated to Atia, an alGama’a military leader. Although the evidence may not have established any particular plan of action to execute the fatwa, a reasonable jury could have found beyond a reasonable doubt from the fatwa’s exhortations and Atia’s readiness to act on it that there was a concrete, illegal objective to murder persons abroad.
A review of the transcripts of various intercepted telephone conversations introduced into evidence, particularly the September 18, 2000, conversation involving Sattar, Taha, and another party, bolsters this conclusion. The discussion goes well beyond the abstract and contemplates the coordination with Atia of violent actions, presumably along the lines of the Luxor massacre. In light of such evidence, a rational jury could have found beyond a reasonable doubt that the conspiracy as charged in Count Two existed.
2. Proof of Material Support to the Conspiracy. Stewart and Yousry also assert that they did not provide material support in the form of “personnel” to the Count-Two conspiracy. A reasonable jury *115could have concluded otherwise. There was evidence introduced at trial sufficient to support a reasonable juror’s inference that Stewart and Yousry helped Abdel Rahman participate covertly in the conspiracy to engage in violence abroad by communicating to members of al-Gama’a and others his withdrawal of support for the cease-fire. Abdel Rahman’s instrumental participation — indeed, his leadership— would, as the district court observed, have been unavailable to the Count-Two conspiracy “without the active participation of Stewart and Yousry.” Sattar V, 395 F.Supp.2d at 95.
The defendants argue that the government established only that they provided the underlying conspiracy with Abdel Rah-man’s “pure speech” and therefore did not provide “personnel” within any constitutional interpretation of section 2339A. The government does not deny that section 2339A may not be used to prosecute mere advocacy or other protected speech, but contends that the defendants were prosecuted for criminal actions that did not amount to protected speech.
Resolution of this dispute does not turn on whether the prosecution introduced evidence of “pure speech.” “Numerous crimes under the federal criminal code are, or can be, committed by speech alone,” and certain crimes “are characteristically committed through speech.” Rahman, 189 F.3d at 117. The issue is, instead, whether Abdel Rahman’s statements were protected speech. We conclude that the statements were not protected such as to cast doubt on the convictions.
Words that are “the very vehicle of [a] crime” are not protected “merely because, in part, [the crimes] may have involved the use of language.” United States v. Rowlee, 899 F.2d 1275, 1278 (2d Cir.), cert. denied, 498 U.S. 828, 111 S.Ct. 87, 112 L.Ed.2d 59 (1990). As we recognized when affirming Abdel Rahman’s sentence, “freedom of speech and of religion do not extend so far as to bar prosecution of one who uses a public speech or a religious ministry to commit crimes.” Abdel Rahman, 189 F.3d at 116-17. “[I]f the evidence shows that the speeches crossed the line into criminal solicitation, procurement of criminal activity, or conspiracy to violate the laws, the prosecution is permissible.” Id. at 117. Words “that instruct, solicit, or persuade others to commit crimes of violence ... violate the law and may be properly prosecuted regardless of whether they are uttered in private, or in a public speech, or in administering the duties of a religious ministry.” Id.
The dissemination of some of the speech introduced at trial might be viewed as nothing more than the expression of views on the broad political situation in Egypt. For example, in reaffirming that he was withdrawing his support for the cease-fire, Abdel Rahman said that he had “expressed [his] opinion and left the matters to [his] brothers to examine it and study it.” Statement for Release, Abdel Rah-man, June 20, 2000.
But a reasonable jury could have found, in light of Abdel Rahman’s role as “spiritual” leader of al-Gama’a, that his messages were ultimately intended to sway alGama’a members to end the cease-fire, and by implication to commit criminal acts of violence. Abdel Rahman’s statements were therefore not an expression of opinion, but a call to arms.
The evidence establishes, moreover, more than a one-way broadcast of Abdel Rahman’s views. Abdel Rahman’s comments were made in direct response to solicitations of his views from other alGama’a members who were seeking to effect an end to the cease-fire and to resume violence. In light of the information avail*116able to Abdel Rahman at the time, a reasonable jury could have read his statements as tailored to and necessary for alGama’a’s operations and increased use of violence. Viewed through this lens, Abdel Rahman’s statements were not materially different in substance from a crime boss making decisions about his criminal enterprise from prison and ordering a “hit.”
3. Proof Regarding Knowing or Intentional Provision of Material Support. Stewart and Yousry argue that the prosecution did not prove the requisite mental state to sustain their convictions. They contend that they were not aware of the existence of the conspiracy charged in Count Two and therefore could not have intended to aid it.
These arguments are unavailing. From the evidence at trial, a reasonable factfinder could have concluded that Stewart and Yousry knew (1) that an active group of people within al-Gama’a including, most notably, Taha, sought to commit violent crimes but were hindered by the cease-fire and by those members of al-Gama’a who sought to adhere to it; (2) that the support of Abdel Rahman — a key leader of the group — was critical to the continued maintenance of the cease-fire; and (3) that, in light of the letters and messages from Taha and Sattar that Yousry read to Abdel Rahman in prison, Abdel Rahman’s particular opinion regarding the cease-fire — and not the view of any other person — would be dispositive on the question of whether al-Gama’a members would continue to abide by the cease-fire. A reasonable fact-finder could thus have concluded that Yousry and Stewart actively and intentionally facilitated communications between Abdel Rahman and al-Gama’a, in part by engaging in various ruses during the course of their visits to Abdel Rahman, and thereby effectively delivered Abdel Rahman’s order to commit violence. Stewart also did so by reaffirming to the press Abdel Rahman’s stated withdrawal of support for the cease-fire, thereby dispelling any notion that the message came not from Abdel Rahman himself, but was instead fabricated by members of the pro-violence faction of al-Gama’a.
C. Other Challenges with Respect to 18 U.S.C. § 2839A
1. Vagueness. Section 2339A criminalizes the provision of material support or resources “knowing or intending” that they are to be used to assist in certain enumerated crimes of terrorism. 18 U.S.C. § 2339A(a) (full text set forth on page 113, supra). Stewart and Yousry assert that insofar as the statute does not require “conscious, knowing intent” or “knowledge and intent,” the statute is unconstitutionally vague as applied to them. They argue that the district court should have dismissed the section 2339A charges for substantially the same reasons that it dismissed the section 2339B charges that were contained in the initial indictment. The government urges to the contrary that the text of section 2339A, which requires “knowing or intending,” 18 U.S.C. § 2339A(a) (emphasis added), is sufficiently precise.
In analyzing the defendants’ arguments in this regard, we must focus on two major differences between the initial and superseding indictment.
First, the statutes upon which they were based differ. Unlike section 2339A, section 2339B penalizes the knowing provision of material support alone. Unlike section 2339A, section 2339B does not require for conviction proof that the defendant has provided support or resources with the knowledge or intent that such resources be used to commit specific violent crimes.20
*117Second, the factual bases for the charges differ. In the initial indictment, the government alleged that the defendants violated section 2339B by the “provision” of “communications equipment” to the conspiracy, Sattar I, 272 F.Supp.2d at 357, and the “provision” of themselves as “personnel” to the conspiracy, id. at 358. In the superseding indictment, the government charged instead that the defendants acted with the “knowledge or intent” to provide material support. And rather than proceeding on the theory that the defendants provided themselves as “personnel” to the conspiracy, the superseding indictment alleges that the defendants provided Abdel Rahman as the “personnel.”
As we have explained, the district court dismissed the section 2339B charges on the ground that they were unconstitutional as applied to the defendants. The basis for dismissal of the “communications equipment” charges was that the statute, as read to apply to the facts of this case, could “criminaliz[e] the mere use of phones and other means of communication [with] neither notice nor standards for [the statute’s] application.” Id. And the basis for the dismissal of the “personnel” charges, as framed in the initial indictment, was that such a charge could criminalize the actions of “ [s]omeone who advocates the cause of the [Foreign Terrorist Organization].’ ” Id. at 359 (quoting Humanitarian Law Project v. Reno, 205 F.3d 1130, 1137 (9th Cir.2000), cert. denied, 532 U.S. 904, 121 S.Ct. 1226, 149 L.Ed.2d 136 (2001)) (brackets omitted). Without more, the district court concluded, such conduct cannot be punished without violating the First Amendment. See id.
The initial charges raised the possibility, moreover, that under the government’s reading of the statute, “a lawyer, acting as an agent of her client, an alleged leader of an FTO, could [be] subject to criminal prosecution as a ‘quasi-employee.’ ” Id. As we shall see, the charges in the superseding indictment do not pose this risk.
A statute is unconstitutionally vague as applied “if it fails to provide people of ordinary intelligence a reasonable opportunity to understand what conduct it prohibits” or “if it authorizes or even encourages arbitrary and discriminatory enforcement.” Hill v. Colorado, 530 U.S. 703, 732, 120 S.Ct. 2480, 147 L.Ed.2d 597 (2000); accord United States v. Rybicki, 354 F.3d 124, 132 (2d Cir.2003) (en banc), cert. denied, 543 U.S. 809, 125 S.Ct. 32, 160 L.Ed.2d 10 (2004). As a general matter, scienter requirements may “ameliorate[ ]” concerns of improper notice. See Hill, 530 U.S. at 732, 120 S.Ct. 2480.
We are satisfied that section 2339A’s knowledge-or-intent formulation saves the statute from being unconstitutionally vague as applied here. Unlike the application of section 2339B proposed in the initial indictment, the superseding indictment required the jury to find that the defendants knew or intended the criminal uses to which the conspiracy would put the material support they provided, thereby eliminating concerns about inadequate notice. In other words, if Stewart and Yousry knew that their actions provided material support to a conspiracy to end the cease-fire and thereby unloose deadly acts of terrorism by al-Gama’a and others, then they were on notice that what they were doing was prohibited by a statute that criminalizes the provision of material support “knowing or intending that [such sup*118port is] to be used in preparation for, or in carrying out,” criminal actions. 18 U.S.C. § 2339A.
Stewart and Yousry argue nonetheless that several statutory terms, such as “personnel,” are unconstitutionally vague as applied to them. They note that “personnel,” undefined at the relevant time, applies equally to sections 2339A and 2339B, compare id. § 2339A(b)(l) (2000) with id. § 2339B(g)(4) (2000).21 They point out that the district court held this term to be unconstitutionally vague in Sattar I. See 272 F.Supp.2d at 360.
We agree, however, with the district court’s conclusion that “[t]he meaning of ‘personnel’ is clear in the context of § 2339A when applied to personnel who are to be used in preparation for, or in carrying out, specific crimes.” Sattar III, 314 F.Supp.2d at 301 n. 11. By applying, in the first indictment, the prohibition against providing “personnel” to the conspiracy to a circumstance in which the defendants provided themselves, the government created a situation in which the defendants could be punished for, in effect, providing themselves to speak out in support of the program or principles of a foreign terrorist organization, an activity protected by the First Amendment. See Sattar I, 272 F.Supp.2d at 359. The more limited charge that they knowingly or intentionally provided Abdel Rahman (as “personnel”), whose voice of command or words of approbation were a means by which al-Gama’a members could prepare for, or carry out, terrorist acts in Egypt, does not carry the same risk with its corresponding constitutional implications.
In addition, the heightened scienter requirement in section 2339A constrains prosecutorial discretion, and ameliorates concerns of arbitrary and discriminatory enforcement. Similar scienter requirements have saved other statutes from void-for-vagueness challenges. See, e.g., Hill, 530 U.S. at 732, 120 S.Ct. 2480; see also Colautti v. Franklin, 439 U.S. 379, 395 & n. 13, 99 S.Ct. 675, 58 L.Ed.2d 596 (1979) (citing cases); United States v. Curdo, 712 F.2d 1532, 1543 (2d Cir.1983).
2. Nature of the Offense. Stewart and Yousry also contend that Count Four, alleging a conspiracy to violate section 2339A, acts impermissibly as a charge of a “multi-level inchoate offense,” a “logical absurdity” that “violate[s] due process.” Stewart Br. 161-65. The gist of their argument is that the charge effectively criminalizes a “conspiracy to conspire,” thereby violating due process by extending criminal liability to a degree too remote from any substantive criminal offense to pass constitutional muster. Id. at 165-69. *119We need not consider this argument;22 Count Five charges the knowing provision of aid — a substantive, not inchoate, offense — and Count Four, pursuing a conspiracy to commit that substantive offense, functions as a traditional conspiracy charge.
As what seems to us to be a variation on the same theme, Stewart and Yousry assert that the district court erred by “impermissibly diluting]” the proof required for conviction of the Counh-Two conspiracy in the context of the material support convictions under section 2339A. Stewart Br. 158. But the government need not have established beyond a reasonable doubt that Stewart or Yousry engaged in a conspiracy to kidnap or commit murder abroad; neither was charged with doing either. Instead, both were charged with and convicted of violating section 2339A, and, as discussed, the evidence is sufficient to sustain the conviction on those charges. Stewart and Yousry do not, presumably because they cannot, suggest that Congress did not have the power to criminalize the relevant underlying conduct.
V. Counts Six and Seven
Stewart challenges her convictions on Counts Six and Seven for violating the blanket provisions of 18 U.S.C. § 1001, which subjects to criminal sanctions
whoever, in any matter within the jurisdiction of the executive, legislative, or judicial branch of the Government of the United States, knowingly and willfully—
(1) falsifies, conceals, or covers up by any trick, scheme, or device a material fact;
(2) makes any materially false, fictitious, or fraudulent statement or representation; or
(3) makes or uses any false writing or document knowing the same to contain any materially false, fictitious, or fraudulent statement or entry....
18 U.S.C. § 1001(a). Stewart argues that, at worst, she broke a promise, and that the statute criminalizes false statements, not false promises.
We conclude otherwise. On May 16, 2000, Stewart signed an affirmation stating that she would (“shall”) abide by the SAMs. On May 26, 2000, Stewart submitted the affirmation to the United States Attorney’s Office for the Southern District of New York. On May 7, 2001, Stewart signed a revised affirmation to the same effect and telecopied it to the same office. Before, after, and between executing these affirmations, she helped smuggle messages to and from Abdel Rahman in violation of the SAMs.
Stewart at least thrice affirmed “under the penalties of perjury the truth” of certain statements. The May 16, 2000, statement reads in pertinent part:
I ... understand that neither I nor any member of my office shall forward any mail received from inmate Abdel Rah-man to a third person. Nor shall I use my meetings, correspondence or phone calls with Abdel Rahman to pass messages between third parties (including, but not limited to, the media) and Abdel Rahman.
Stewart May 2000 Aff. (Gov’t Ex. 7.) In the May 7, 2001, statement, Stewart affirmed:
I ... specifically understand that the meetings shall not be for the purpose of presenting statements to the defense team for further dissemination to third parties, including the media. I will only *120allow the meetings to be used for legal discussion between Abdel Rahman and me.
Stewart May 2001 Aff. (Gov’t Ex. 12.)
A reasonable factfinder was entitled to conclude that Stewart affirmed under penalty of perjury that she had the then-present intent to have her actions conform to the terms of the SAMs. From Stewart’s smuggling messages to and from Abdel Rahman, the factfinder could conclude that the assertion about her intent was knowingly and willfully false when it was made. See United States v. Uram, 148 F.2d 187, 189 (2d Cir.1945) (concluding that allegation of a false representation as to future use of loan proceeds was “an allegation of a present statement and the assertion of existing intent”); cf. United States v. Shah, 44 F.3d 285, 294 (5th Cir.1995) (observing that “a promise may amount to a ‘false, fictitious or fraudulent’ statement if it is made without any present intention of performance and under circumstances such that it plainly, albeit implicitly, represents the present existence of an intent to perform”).
Stewart seeks support for her argument from Williams v. United States, 458 U.S. 279, 102 S.Ct. 3088, 73 L.Ed.2d 767 (1982). There, the Supreme Court reversed a conviction of the defendant under 18 U.S.C. § 1014 for his making of a “false statement” — a check drawn on an account containing insufficient funds — for the purpose of influencing the actions of a federally insured institution. But central to the Williams Court’s analysis was the proposition that a check, even a bad check, “is not a factual assertion at all.” Id. at 284, 102 S.Ct. 3088. A check “d[oes] not, in terms, make any representation as to the state of [the drawer’s] bank balance” but “serve[s] only to direct the drawee banks to pay the face amounts to the bearer, while committing [the drawer] to make good the obligations if the banks dishonor! ] the drafts.” Id. at 284-85,102 S.Ct. 3088.
Williams does not apply to the conduct at issue here. A reasonable jury could have concluded that Stewart’s affirmations that she would abide by the SAMs amounted to factual assertions regarding her then-present intent to abide by the SAMs. Based on her repeated affirmations, and her repeated violations of those affirmations, moreover, a reasonable jury could have concluded that at the time Stewart executed and submitted the affirmations at issue, she did not intend to abide by them — in other words, that her representations were knowingly false when made. On this basis, a reasonable jury could have properly concluded that Stewart violated section 1001 as charged in Counts Six and Seven.
VI. General Challenges to the Validity of the Convictions
In addition to their challenges to specific counts in the indictment, Stewart and Sat-tar make general assertions of error regarding the government’s conduct during the course of the prosecution. Stewart argues that she was selectively prosecuted on account of her gender and political beliefs, and both Stewart and Sattar assert that the government’s decision to file a superseding indictment following their successful efforts to dismiss several counts of the initial indictment constitutes vindictive prosecution.
The defendants also raise various challenges to the district court’s case administration. First, they allege a variety of pretrial errors: in the denial of their motions to sever their trial from Sattar’s; in the empaneling of an anonymous jury; in the denial of Stewart’s motion to suppress certain evidence obtained pursuant to the Foreign Intelligence Surveillance Act of 1978, Pub.L. No. 95-511, 92 Stat. 1783, 50 *121U.S.C. §§ 1801 et seq. (“FISA”); and in the denial of Stewart’s motion for disclosure of whether she, her co-defendants, or others were subject to surveillance by the National Security Agency. The defendants also argue that the district court made various evidentiary errors. Finally, the defendants argue that the district court erred in addressing post-conviction claims of juror misconduct.
A. Selective Prosecution
Stewart argues that she was selectively prosecuted on account of her gender and political beliefs in violation of the Equal Protection Clause of the Fourteenth Amendment. This argument requires Stewart to establish that she was “treated differently from other similarly situated individuals” and that “such differential treatment was based on impermissible considerations such as race, religion, intent to inhibit or punish the exercise of constitutional rights, or malicious or bad faith intent to injure [her].” Harlen Assocs. v. Inc. Vill. of Mineola, 273 F.3d 494, 499 (2d Cir.2001) (internal quotation marks omitted); accord United States v. Fares, 978 F.2d 52, 59 (2d Cir.1992); United States v. Moon, 718 F.2d 1210, 1229 (2d Cir.1983), cert. denied, 466 U.S. 971, 104 S.Ct. 2344, 80 L.Ed.2d 818 (1984).
Stewart compares her treatment with that of Abdel Rahman’s former lawyers Ramsey Clark and Abdeen Jabara, who, even though they allegedly violated the same SAMs as she did, were not prosecuted for doing so. Clark’s and Jabara’s alleged misconduct, however, was different from Stewart’s adjudicated misconduct in at least one crucial respect: both Clark and Jabara refused to publicize Abdel Rahman’s withdrawal of support for the alGama’a cease-fire, something Stewart did at least twice. Like Stewart, Clark spoke to the media on Abdel Rahman’s behalf. But unlike Stewart, the message Clark disseminated in apparent violation of the SAMs — that Abdel Rahman did not support the formation of a political party in Egypt — did not have the same potential for inciting violence. For that reason and those set forth by the district court in its decisions addressing the matter, see Sattar V, 395 F.Supp.2d at 103 (denying selective prosecution claim), cf. Sattar III, 314 F.Supp.2d at 311-14 (denying vindictive prosecution claim), and Order, Sept. 1, 2004 (denying selective prosecution claim), Stewart’s arguments in this regard are without merit.23
B. Vindictive Prosecution
Sattar argues that the district court erred in denying his motion to dismiss the Count-Two conspiracy charge in the superseding indictment because the institution of the charge was driven by prosecutorial vindictiveness. This argument is also without merit.
The government filed the original five-count indictment in April 2002. In it, Sat-tar, Stewart, Yousry, and another24 were *122charged with providing, attempting to provide, and conspiring to provide material support and resources to an FTO in violation of 18 U.S.C. § 2339B. Sattar moved to dismiss these charges on the ground that section 2339B was unconstitutionally vague as applied to the allegations in the indictment. By opinion and order dated July 22, 2003, the district court agreed with Sattar. Sattar I, 272 F.Supp.2d at 358-61. Following that decision, the government filed a superseding indictment adding a new count charging Sattar with conspiring to murder persons in a foreign country in violation of 18 U.S.C. § 956.
Sattar argues that the government’s decision to file the superseding indictment and add the charge of violating section 956 “was a retaliatory act ... motivated by the embarrassment [the government] suffered as a result of the dismissal” of two central counts in the original indictment. Sattar Br. 17. He asserts that an inference of vindictive prosecution is supportable in two ways: First, the addition of Count Two— which carries a potential sentence of life imprisonment, a longer sentence than that authorized by the dismissed charge pursuant to section 2339B — “up[ped] the ante” for the consequences of conviction. Sattar III, 314 F.Supp.2d at 311. Second, the government could have brought the section 956 charge in the original indictment, inasmuch as it was based on information known to the government prior to the filing of the initial indictment, but the government declined to do so.
“[T]he decision as to whether to prosecute generally rests within the broad discretion of the prosecutor, and a prosecutor’s pretrial charging decision is presumed legitimate.” United States v. Sanders, 211 F.3d 711, 716 (2d Cir.), cert. denied, 531 U.S. 1015, 121 S.Ct. 574, 148 L.Ed.2d 491 (2000) (citations and internal quotation marks omitted). Nonetheless, “a prosecution brought with vindictive motive, penalizing those who choose to exercise constitutional rights, would be patently unconstitutional.” Id. (internal quotation marks omitted). We will dismiss an indictment if actual vindictiveness has been demonstrated, or if, under the circumstances, “there is a presumption of vindictiveness that has not been rebutted by objective evidence justifying the prosecutor’s action.” Id. (internal quotation marks omitted).
We review a district court’s factual findings on prosecutorial vindictiveness for clear error, and its legal conclusions de novo. United States v. Johnson, 171 F.3d 139, 140 (2d Cir.1999) (per curiam). We review a district court’s decision denying discovery on claims of prosecutorial vindictiveness for abuse of discretion. Sanders, 211 F.3d at 717.
“Th[e] need to avoid the appearance of vindictiveness has taken the form of a presumption of prosecutorial vindictiveness ..., applied when (but only when) the circumstances of a case pose a ‘realistic likelihood’ of such vindictiveness.” United States v. King, 126 F.3d 394, 397 (2d Cir. 1997) (citations and internal quotation marks omitted). The district court found no reason to presume that the actions at issue, which arose in a pretrial setting, were vindictive. See Sattar III, 314 F.Supp.2d at 311-12.
“The circumstances must present a realistic likelihood of vindictiveness that would be applicable in all cases, and any such presumption may be overcome by objective evidence justifying the prosecutor’s action.” Sanders, 211 F.3d at 717 (citations and internal quotation marks omitted). “[T]his court has consistently adhered to the principle that the presumption of prosecutorial vindictiveness does not exist in a pretrial setting.” Paradise v. CCI Warden, 136 F.3d 331, 335 (2d Cir.), cert. denied, 525 U.S. 836, 119 S.Ct. 94, 142 *123L.Ed.2d 74 (1998) (internal quotation marks omitted); see also Sanders, 211 F.3d at 717 (same). Sattar provides no reason for us to deviate from this general rule here, and no basis upon which we can conclude that the district court’s findings in this respect were clearly erroneous.
Sattar’s claim of actual, as opposed to presumptive, vindictiveness is also without merit. A finding of actual vindictiveness requires a showing that a “prosecutor’s charging decision [is] a ‘direct and unjustifiable penalty,’ that resulted ‘solely from the defendant’s exercise of a protected legal right.’ ” Sanders, 211 F.3d at 716-17 (internal citation omitted). The evidence Sattar offers in this regard is that the government possessed the same information when preparing the original and superseding indictments, that the maximum punishment Sattar faced if convicted under the superseding indictment was greater than that he faced if convicted under the original indictment, and that the superseding indictment was the result of the district court’s dismissal of the section 2339B material support charges in the original indictment. We have no warrant to conclude that the district court clearly erred in finding that the charging decision was not vindictive, or that the government was attempting to do anything more than hold Sattar criminally responsible for engaging in the underlying acts that form the basis of the indictment. See Paradise, 136 F.3d at 336. Put another way, it does not follow from the facts Sattar recites that the resulting charge was necessarily brought vindictively; for this reason the district court did not err in concluding otherwise.
C. Trial Administration
1. Alleged Pre-Trial Errors
a. Severance
Stewart and Yousry assert that the district court abused its discretion by denying their motions to sever their trial from the trial of Sattar because Sattar was charged with, and convicted of, conspiracy to murder persons in a foreign country— allegations different from and more serious than those with which Stewart and Yousry were charged. To succeed on this argument, Stewart and Yousry must show that the district court abused its discretion in this regard and that the resulting prejudice rose to the level of “a miscarriage of justice.” See United States v. Yousef, 327 F.3d 56, 150 (2d Cir.2003). Stewart and Yousry complain primarily that as a result of the district court’s denial of their motion for severance, evidence irrelevant to their actions and unfairly prejudicial to their case permeated the trial. They further contend that the volume of limiting instructions given to the jury rendered them effectively useless in attempting to curb any prejudicial effect.
But the district court did not abuse its discretion in this respect. Count Two charged Sattar with conspiring to murder persons in a foreign country. Count Five charged Stewart and Yousry with providing and concealing material support to that conspiracy, and Count Four charged them with conspiring to provide and conceal that support. Most of the evidence against Sattar that Stewart and Yousry assert to have been unduly prejudicial to them— evidence submitted to establish the existence of the Count-Two conspiracy charge against Sattar — would have been admissible against Stewart and Yousry even had the trial been severed. See Sattar I, 272 F.Supp.2d at 380-81. This is so because the Count-Two conspiracy was an element of the crimes charged against Stewart and Yousry in Counts Four and Five, and the government would have been entitled, and expected, to elicit relevant evidence regarding its existence. “[T]he fact that tes*124timony against a codefendant may be harmful is not a ground for severance if that testimony would also be admissible against the moving defendant tried separately.” United States v. Rosa, 11 F.3d 315, 341 (2d Cir.1993), cert. denied, 511 U.S. 1042, 114 S.Ct. 1565, 128 L.Ed.2d 211 (1994).
To the extent that evidence introduced at trial was not admissible against a particular defendant, the district court gave detailed — if necessarily voluminous — curative instructions to the jury. Neither Stewart nor Yousry proffer instructions that should have been given, but were not. Nor do they identify improper curative instructions that were given. This is not a case where “the risk that the jury [would] not, or [could] not, follow instructions [was] so great, and the consequences of failure so vital to the defendant, that the practical and human limitations of the jury system [could not] be ignored.” Bruton v. United States, 391 U.S. 123, 135, 88 S.Ct. 1620, 20 L.Ed.2d 476 (1968). Despite the length of the instructions, we presume, as did the district court, see Sattar V, 395 F.Supp.2d. at 104, that the jurors followed them, see, e.g., Richardson v. Marsh, 481 U.S. 200, 206, 107 S.Ct. 1702, 95 L.Ed.2d 176 (1987) (noting that it is an “almost invariable assumption of the law that jurors follow their instructions”); United States v. Salameh, 152 F.3d 88, 116 (2d Cir.1998), cert. denied, 525 U.S. 1112, 119 S.Ct. 885, 142 L.Ed.2d 785 (1999) (“Juries are presumed to follow their instructions.” (internal quotation marks and brackets omitted)). Neither Stewart nor Yousry provide us with a convincing reason to conclude that the district court abused its discretion in this regard.
b. Empaneling an Anonymous Jury
By order dated April 29, 2004, the district court granted the government’s motion to empanel an anonymous jury, in light of the substantial publicity surrounding the case and the seriousness and nature of the charges in the indictment, especially the charge that the defendants had attempted “to interfere with the ordered procedures of law enforcement and the judicial process.” Order, Apr. 29, 2004. As a general rule, a district court may order the empaneling of an anonymous jury upon “(a) concluding that there is strong reason to believe the jury needs protection, and (b) taking reasonable precautions to minimize any prejudicial effects on the defendant and to ensure that his fundamental rights are protected.” United States v. Paccione, 949 F.2d 1183, 1192 (2d Cir.1991), cert. denied, 505 U.S. 1220, 112 S.Ct. 3029, 120 L.Ed.2d 900 (1992). A defendant’s apparent “willingness to tamper with the judicial process” will support the use of an anonymous panel. United States v. Aulicino, 44 F.3d 1102, 1116 (2d Cir.1995) (internal quotation marks and ellipses omitted). Where otherwise warranted,
the use of an anonymous jury does not infringe a defendant’s constitutional rights, so long as the court conducts a careful voir dire designed to uncover any bias as to the issues or the defendants and takes care to give the jurors a plausible and non-prejudicial reason for not disclosing their identities.
Id. If “there is evidence to support the district court’s finding of reason to believe the jury needs protection,” and if “the court has taken reasonable precautions to minimize any prejudicial effects on the defendant and to ensure protection of his fundamental rights, the decision to empanel an anonymous jury is reviewed only for abuse of discretion.” United States v. Thai, 29 F.3d 785, 801 (2d Cir.), cert. denied, 513 U.S. 977, 115 S.Ct. 456, 130 L.Ed.2d 364 (1994).
*125In light of (a) the charges against the defendants, which included a terrorist conspiracy to murder, and Stewart’s and Yousry’s alleged provision of material support to that conspiracy; (b) the reasonable likelihood that the pervasive issue of terrorism would raise in the jurors’ minds a fear for their individual safety; (c) the fact that the charges against Stewart and Yousry were in significant part about their alleged corruption of the judicial process; (d) the widespread pretrial publicity about the case; and (e) the extensiveness of the voir dire administered to the jury by the court, we conclude that the district court did not abuse its discretion.
c. Pre-Trial Suppression of Evidence
i. Suppression of Evidence Obtained Pursuant to FISA The defendants argue that evidence obtained from electronic surveillance pursuant to FISA should have been suppressed because such surveillance was improperly instituted for the purpose of a criminal investigation, rather than for the gathering of intelligence, and because FISA was unconstitutional as applied in this case.
By Opinion and Order dated September 15, 2003, the district court denied the defendants’ motions to suppress the relevant evidence. Sattar II, 2003 WL 22137012, at *22, 2003 U.S. Dist. LEXIS 16164, at *70. At a pretrial hearing held on April 9, 2002, the government informed the district court and the defendants that it had
conducted a series of court-authorized electronic surveillance over a period of several years authorized under [FISA], consisting of the electronic surveillance of defendant Sattar’s home phone, his computer, [and] fax machine, [and] defendant Yousry’s telephone. The government also monitored several prison visits, both audio and video, to Sheik Abdel Rahman over the past several years, one of which involved defendant Stewart in May of 2000.
Id. at *2, 2003 U.S. Dist. LEXIS 16164, at *6. A month later, by letter dated May 8, 2002, the government also informed the defendants that “information obtained or derived pursuant to the authority of the FISA was used, and will, continue to be used, in connection with the prosecution of [this] case.” Id.; see 50 U.S.C. § 1806(c) (providing that where the government intends to disclose information obtained from FISA surveillance, the government “shall, prior to the trial ... notify the aggrieved person and the court ... that the Government intends to so disclose or so use such information”).
As part of its pretrial obligations under FISA, the government
made extensive disclosures to the defendants, including over 85,000 audio recordings of voice calls, fax-machine sounds, and computer-modem sounds obtained through audio surveillance of telephone numbers used by Sattar and Yousry; the FBI’s written summaries ... of approximately 5,300 voice calls that the FBI deemed to contain foreign intelligence information and therefore did not minimize; approximately 150 draft transcripts of voice calls; and approximately 10,000 pages of e-mails obtained through electronic surveillance of an e-mail account used by Sattar. The Government has also disclosed certain evidence solely to Stewart and Yousry, including audiotapes of 63 telephone conversations between the imprisoned Sheikh Abdel Rahman and his attorneys and Yousry, and audio and video recordings of three prison visits to Sheikh Abdel Rahman by his attorneys and Yousry on February 19, 2000, May 19 and 20, 2000, and July 13 and 14, 2001.
Sattar II, 2003 WL 22137012, at *2, 2003 U.S. Dist. LEXIS 16164, at *7.
*126In accordance with the procedure set forth in FISA, see 50 U.S.C. § 1806(e), Sattar and Stewart moved to suppress the evidence arising out of the FISA surveillance, and for access to classified information regarding that surveillance. The government argues on appeal, as it did before the district court, that the FISA surveillance at issue was lawfully authorized and conducted. The government moved the district court to order that none of the classified documents or classified information contained therein would need to be disclosed to the defendants. Pursuant to 50 U.S.C. § 1806(f), the government requested that the court conduct an in camera and ex parte review of the materials and proffered an affidavit of then-Attorney General John Ashcroft stating, in relevant part, that “it would harm the national security of the United States to disclose or have an adversary hearing with respect to materials submitted to the United States Foreign Intelligence Surveillance Court ... in connection with this matter.” Sattar II, 2003 WL 22137012, at *5, 2003 U.S. Dist. LEXIS 16164, at *18.
After reviewing the classified materials, the district court concluded that “all of the requirements of FISA were satisfied” and “each of the FISA surveillances was authorized by a FISA Court order that complied with the statutory requirements for such orders and was supported by the statements and certifications required by the statute.” Id. at *6, 2003 U.S. Dist. LEXIS 16164, at *21. The district court also concluded that this was “not a case where disclosure [of the classified FISA materials] was necessary or where a review of all of the materials suggested that due process required disclosure to the defendants.” Id. at *6, 2003 U.S. Dist. LEXIS 16164, at *22.
On appeal, Stewart argues that the materials generated pursuant to the FISA surveillance should have been suppressed because the surveillance was instituted for the purposes of a criminal investigation, not for the purpose of intelligence gathering. In addition, Stewart contends that the FISA review process lacks meaningful judicial review, and that due process required that her counsel have access to the FISA applications and warrants.
Stewart’s attacks on the constitutionality of the FISA statute are foreclosed by this Court’s decision in United States v. Duggan, 743 F.2d 59 (2d Cir.1984), which, despite its age, remains binding precedent in this Circuit. There, we concluded that “the procedures fashioned in FISA [are] a constitutionally adequate balancing of the individual’s Fourth Amendment rights against the nation’s need to obtain foreign intelligence information.” Id. at 73.
Congress created the FISA system in an attempt to accommodate “the legitimate need of Government for intelligence information and the protected rights of our citizens.” United States v. U.S. District Court, 407 U.S. 297, 322-23, 92 S.Ct. 2125, 32 L.Ed.2d 752 (1972). As we have explained, “Congress passed FISA to settle what it believed to be the unresolved question of the applicability of the Fourth Amendment warrant requirement to electronic surveillance for foreign intelligence purposes, and to remove any doubt as to the lawfulness of such surveillance.” Duggan, 743 F.2d at 73 (internal quotation marks omitted). FISA’s primary focus is surveillance for the purpose of gathering foreign intelligence information, which is defined to include “information that relates to, and if concerning a United States person is necessary to, the ability of the United States to protect against [inter alia] international terrorism.” 50 U.S.C. § 1801(e)(1).
FISA established a court (the “FISA Court”) comprised of designated district *127court judges (“FISA Judges”). The FISA Court has jurisdiction over applications for electronic surveillance relating to the gathering of potential foreign intelligence information under the procedures set forth in FISA. See id. § 1803. FISA generally permits a federal officer, when authorized by the President of the United States acting through the Attorney General, to obtain from any FISA Judge an order “approving electronic surveillance of a foreign power or an agent of a foreign power for the purpose of obtaining foreign intelligence information.” Id. § 1802(b). “[A] group engaged in international terrorism or activities in preparation therefor,” is a “foreign power,” id. § 1801(a)(4), and an “agent of a foreign power” includes any person who “knowingly engages in sabotage or international terrorism, or activities that are in preparation therefor, for or on behalf of a foreign power” or “knowingly aids or abets any person in [such] conduct,” id. § 1801(b)(2)(C) & (E).
In order to secure an order authorizing surveillance from a FISA Judge, the officer’s application must meet the statutory requirements set forth in 50 U.S.C. § 1804. For example, the application must set forth the identity or description of the target of the surveillance, id. § 1804(a)(2), and a statement of facts and circumstances relied upon to justify the officer’s belief that the target is a foreign power or agent of a foreign power and that each facility or location to be subjected to surveillance is being used or is about to be used by the target, id. § 1804(a)(3). Prior to October 26, 2001, such a federal officer was required to certify to the FISA judge that “the purpose” of the FISA surveillance was the interception of foreign intelligence information. See id. § 1804(a)(7)(B) (2000). In Duggan, we interpreted this provision to mean that the interception of foreign intelligence information must be the “primary objective” of the surveillance. Duggan, 743 F.2d at 77. The statute was changed in the wake of the events of September 11, 2001, however, to require only that “a significant purpose” of the surveillance be the interception of such information. See 50 U.S.C. § 1804(a)(7)(B)(2003); see also 50 U.S.C. § 1804(a)(6)(B) (2008) (redesignated from (a)(7)).
Only after a FISA Judge has been satisfied that the application meets FISA’s requirements will he or she authorize the surveillance. To enter an order approving surveillance, the FISA Judge must find that the application was properly filed and properly authorized by the Attorney General; that associated procedures designed to minimize the acquisition and retention of non-publicly available information concerning “United States persons” satisfy FISA’s requirements, see id. § 1801(h); that the facts set forth in the application provide probable cause to believe that the target is a foreign power or agent of such a power; and that the locations to be subject to surveillance are being used, or are about to be used, by the target, id. § 1805(a).
When the application is complete and properly certified by an executive branch official, however,
it is, under FISA, subjected to only minimal scrutiny by the courts. Congress deemed it a sufficient check in this regard to require the FISA Judge (1) to find probable cause to believe that the target of the requested surveillance is an agent of a foreign power; (2) to find that the application is complete and in proper form; and (3) when the target is a United States person, to find that the certifications are not “clearly erroneous.”
Duggan, 743 F.2d at 77. Stewart’s argument that FISA does not ensure adequate *128judicial view is therefore foreclosed by Duggan. See id. at 77 & n. 6.
Although the purpose of the surveillance must be to obtain foreign intelligence information, “otherwise valid FISA surveillance is not tainted simply because the government can anticipate that the fruits of such surveillance may later be used ... as evidence in a criminal trial.” Id. at 78. To the contrary, the statute specifically contemplates the introduction of FISA surveillance evidence in criminal prosecutions. See 50 U.S.C. § 1806(b). As both Congress and this Court have recognized, “in many cases the concerns of the government with respect to foreign intelligence will overlap those with respect to law enforcement.” Duggan, 743 F.2d at 78.
When such FISA information is introduced in the course of a criminal prosecution, and upon review of a suppression motion, the trial court has the opportunity to review the FISA Court’s order, issued pursuant to 50 U.S.C. § 1805, in light of the underlying applications for surveillance, filed pursuant to 50 U.S.C. § 1804, in order “to determine whether the surveillance [at issue] was lawfully authorized and conducted.” 50 U.S.C. § 1806(f). The district court’s review of the FISA Judge’s decision is, like the FISA Judge’s decision itself, deferential. “[A] reviewing court [has] no greater authority to second-guess the executive branch’s certifications than has the FISA Judge.” Duggan, 743 F.2d at 77.
FISA applications are likely to contain allegedly sensitive information relating to perceived issues of national security. The applications are required to set forth how and why the Executive Branch knows what it knows, which may include references to covert agents and informers. For. this reason, “ ‘ex parte, in camera determination is to be the rule.’ ” Id. at 78 (quoting United States v. Belfield, 692 F.2d 141, 147 (D.C.Cir.1982)). The district court has the “discretion to disclose portions of [relevant materials], under appropriate protective procedures, [but] only if [it] decides that such disclosure is ‘necessary to make an accurate determination of the legality of the surveillance’ ” or is otherwise required by due process. Id. (quoting 50 U.S.C. § 1806(f)).
Stewart argues on appeal that the “primary purpose” of the FISA wiretapping in this case was to pursue a criminal investigation, not to collect foreign intelligence information. The district court, having reviewed the FISA materials, concluded that “all of the surveillance at issue was conducted with the appropriate purpose,” whether with a “primary purpose” or “a significant purpose” to obtain foreign intelligence information. Sattar II, 2003 WL 22137012, at *12-*13, 2003 U.S. Dist. LEXIS 16164, at *40-*42.
Upon our own in camera review of the underlying material and the district court’s order filed under seal, we are confident that the district court did not err in so concluding. Since the interceptions meet the “primary purpose” test, we, like the district court, need not and do not address Stewart’s argument that FISA’s new and less demanding “significant purpose” test is unconstitutional. Cf. In re Sealed Case, 310 F.3d 717, 735 (FISA Ct. Rev.2002) (rejecting the “primary purpose” test in favor of a “significant purpose” test). Similarly, based on the relevant evidence which, as adduced at trial, is outlined above, the district court did not err in finding there to be “ample probable cause to believe that the targets of the relevant surveillance — Sattar, Yousry, and Sheikh Abdel Rahman — were acting as agents of a foreign power” as defined by FISA, i.e., alGama’a, “and that each of the facilities at which the surveillance was directed was being used, or was about to be used, by *129that target.” Sottar II, 2003 WL 22137012, at *7, 2003 U.S. Dist. LEXIS 16164, at *24.
Stewart also argues that she was an inappropriate target of the surveillance. As the district court noted, however, Stewart was never designated as a target in any of the applications at issue; her alleged co-conspirators were. “Once the proper preconditions are established with respect to a particular target, there is no requirement in FISA that all those likely to be overheard engaging in foreign intelligence conversations be named.” Duggan, 743 F.2d at 79. Because Stewart’s co-conspirators were targeted pursuant to proper procedures, the Fourth Amendment did not require that Stewart also be identified or described as a target in order for her intercepted conversations to be used in a criminal prosecution. Id. at 79 n. 7.
Stewart further argues that the district court erred in declining to disclose FISA materials to her counsel. The district court may order disclosure of FISA materials “under appropriate security procedures and protective orders,” but “only where such disclosure is necessary to make an accurate determination of the legality of the surveillance.” 50 U.S.C. § 1806(f). When the district court “determines that the surveillance was lawfully authorized and conducted, it shall deny the motion of the aggrieved person except to the extent that due process requires discovery or disclosure.” Id. § 1806(g).
As we have noted, in these circumstances disclosure is the exception and “ ‘ex parte, in camera determination is [ ] the rule.’ ” Duggan, 743 F.2d at 78. The need to disclose materials to defense counsel may arise if the judge determines there to be “potential irregularities such as possible misrepresentation of fact, vague identification of the persons to be surveilled or surveillance records which include a significant amount of nonforeign intelligence information, calling into question compliance with the minimization standards contained in the order.” Id. (internal quotation marks and brackets omitted). But Stewart does not point to any case where any court has ordered disclosure in a situation similar to hers. Upon our own review of the materials, we conclude that there was no error in the district court’s determination that disclosure was unnecessary for an accurate determination of the legality of the surveillance at issue or to satisfy the requirements of due process.
ii. Disclosure Regarding NSA Surveillance. On June 16, 2006, Stewart moved to compel disclosure as to whether she or any of her co-defendants were subject to surveillance by the National Security Agency (“NSA”). The government filed, ex parte, a classified response to be reviewed in camera. At a hearing on September 25, 2006, the government insisted that its classified submission was properly filed under section 4 of the Classified Information Procedures Act (“CIPA”), Pub.L. No. 96-456, 94 Stat. 2025 (1980) (codified at 18 U.S.C. app. 3). The government also argued that none of the defense counsel was properly cleared for access to the information and that, “without going into the details of the classification level of our submission, I don’t think any defense counsel would ever have a need to know the details of the terrorist surveillance program, especially in this case.” H’g Tr. 13-14, Sept. 25, 2006. Following the hearing and in response to subsequent orders from the district court, the government filed supplemental ex parte confidential responses dated October 6, 2006, October 12, 2006, and October 13, 2006 for in camera review. After additional materials were submitted by the government, the district court granted, in part, the motion for dis*130closure, ordering the government to make specified disclosures,25 but otherwise denied the motion. Order, Oct. 17, 2006, at 2. In that public order, the district court noted that it had filed an “ex parte Order under seal containing classified information which explains in detail the reasons for the Court’s decision,” and found that there was a
compelling reason for filing the additional Order ex parte and under seal because it contains classified information that cannot reasonably be segregated from the other material in the Order, and that such a filing is consistent with the Classified Procedures Act and the rights of the defendants. See [United States] v. Yunis, 867 F.2d 617, 622-25 (D.C.Cir.1989).
Id.
Through CIPA, Congress established procedures for handling classified information in criminal cases. “Classified information” is defined to include “information or material that has been determined by the United States Government pursuant to an Executive order, statute, or regulation, to require protection against unauthorized disclosure for reasons of national security.” 18 U.S.C. app. 3 § 1(a). CIPA is “meant to protect and restrict the discovery of classified information in a way that does not impair the defendant’s right to a fair trial.” United States v. Aref, 533 F.3d 72, 78 (2d Cir.2008) (alterations and internal quotation marks omitted), cert. denied., - U.S. -, 129 S.Ct. 1582, 173 L.Ed.2d 679 (2009).
Section 4 of CIPA establishes procedures for discovery of classified information. It provides:
The court, upon a sufficient showing, may authorize the United States to delete specified items of classified information from documents to be made available to the defendant through discovery under the Federal Rules of Criminal Procedure, to substitute a summary of the information for such classified documents, or to substitute a statement admitting relevant facts that the classified information would tend to prove. The court may permit the United States to make a request for such authorization in the form of a written statement to be inspected by the court alone. If the court enters an order granting relief following such an ex parte showing, the entire text of the statement of the United States shall be sealed and preserved in the records of the court to be made available to the appellate court in the event of an appeal.
18 U.S.C. app. 3 § 4.
This section “clarifies district courts’ power under Federal Rule of Criminal Procedure 16(d)(1) to issue protective orders denying or restricting discovery for good cause,” which includes “information vital to the national security.” Aref, 533 F.3d at 78 (internal quotation marks omitted). CIPA does not itself create a government privilege against the disclosure of classified information; it presupposes one. Id. The “most likely source for the protection of classified information lies in the common-law privilege against disclosure of state secrets.” Id.
*131We have recently held that the state-secrets privilege applies to criminal cases, but that “it must give way under some circumstances to a criminal defendant’s right to present a meaningful defense.” Id. at 79. To determine such circumstances, we have employed the standard first articulated in Roviaro v. United States, 353 U.S. 53, 77 S.Ct. 623,1 L.Ed.2d 639 (1957), in the context of the so-called informer’s privilege in criminal prosecutions, see Aref, 533 F.3d at 79-80.26
First, the district court must determine whether the material in dispute is discoverable, and if so, whether the state-secrets privilege applies. Id. at 80. It applies if “(1) there is ‘a reasonable danger that compulsion of the evidence will expose ... matters which, in the interest of national security, should not be divulged,’ and (2) the privilege is ‘lodged by the head of the department which has control over the matter, after actual personal consideration by that officer.’ ” Id. at 80 (quoting United States v. Reynolds, 345 U.S. 1, 8, 10, 73 S.Ct. 528, 97 L.Ed. 727 (1953)). If the information is discoverable but the privilege applies, then the district court must determine “whether the information is helpful or material to the defense, i.e., useful ‘to counter the government’s case or to bolster a defense.’ ” Id. (citation omitted). In order to be helpful or material, the evidence “need not rise to the level that would trigger the Government’s obligation under Brady v. Maryland, 373 U.S. 83, 83 S.Ct. 1194,10 L.Ed.2d 215 (1963), to disclose exculpatory information.” Id.
We review the district court’s decision to issue a protective order under CIPA section 4 and Federal Rule of Criminal Procedure 16(d)(1) for abuse of discretion. Aref 533 F.3d at 80. Similarly, we review for abuse of discretion the district court’s finding whether evidence is “helpful” or “material to the defense.” Id.
At the time of the district court’s decision and order, our decision in Aref had not yet issued. As noted in the district court’s public order denying the motion to compel, however, the district court relied on an opinion by a sister circuit embracing a test similar to that embraced by the Aref panel. Order, Oct. 17, 2006, at 2 (citing United States v. Yunis, 867 F.2d 617, 622-25 (D.C.Cir.1989)).27
Here, the government has invoked the state-secrets privilege. It asserts that the details of the NSA’s operations, including the surveillance vel non of any particular individual or group, implicate national security and are among “the nation’s most guarded secrets.” Gov’t Br. 389-90; id. *132(quoting Halkin v. Helms, 598 F.2d 1, 7 (D.C.Cir.1978)). Where evidence is intercepted, the sensitive nature of the information might lie “not so much in the contents of the [information], as in the time, place, and nature of the government’s ability to intercept the [information] at all.” Yunis, 867 F.2d at 623.28
In light of these general concerns and the principles set forth in Yunis and Aref, and based on our own review of the underlying materials and the district court’s sealed order, we are satisfied that the district court did not abuse its discretion or otherwise err in denying Stewart’s motion to compel disclosure.
We note, as we did in Aref, which postdated the district court’s order here, the absence of a formal public “claim of privilege[] lodged by the head of the department which has control over the matter, after actual personal consideration by that officer.” Reynolds, 345 U.S. at 7-8, 73 S.Ct. 528; see Aref, 533 F.3d at 80. As in Aref, we conclude that in the pre-Aref context, such a flaw “is not necessarily fatal,” and that “[i]t would ‘be of little or no benefit’ for us to remand for the purpose of having the department head agree that disclosure of the classified information would pose a risk to national security here.” Aref, 533 F.3d at 80. But the absence of the formal claim is not a trivial matter. We do not demean it. We expect that, in light of the holding in Aref, we will not need to address this issue in appeals from future prosecutions in which the state-secrets privilege is invoked as the government is now well-informed of this obligation. Cf. id. (“Based on our holding today ... we trust that this issue will not arise in future CIPA cases.”).
We reject Stewart’s claim that the district court erred in reviewing materials ex parte and in camera. As we noted in Aref, “[b]oth CIPA section 4 and Rule 16(d)(1) authorize ex parte submissions .... When the ‘government is seeking to withhold classified information from the defendant, an adversary hearing with defense knowledge would defeat the very purpose of the discovery rules.’ ” Aref, 533 F.3d at 81.
The CIPA procedures followed by the district court place all parties involved (except perhaps the government) at a substantial disadvantage: defendants are hampered in contesting the assertions that are being made to the court by the government; district courts and courts of appeals are deprived of the opportunity for an adversarial proceeding upon which they are typically dependent in attempting fairly and properly to resolve disputes; and the public, as well as the litigants, are deprived of the assurances that come with public scrutiny of the work of the courts. The procedures are also, of course, subject to abuse by the executive. But a method for protection of classified material is necessary, and these procedures have been established by Congress and held to be constitutional. We, as did the district court, therefore accept them as a necessary, if imperfect, accommodation of the varied interests implicated.
2. Alleged Trial Errors. Both Sattar and Yousry challenge various evidentiary rulings made by the district court. Sattar argues that the court abused its discretion by admitting a book by Taha and a videotape of Taha, Osama Bin Laden, and other al-Gama’a members encouraging violence, and by excluding news footage purporting to depict Israeli *133violence against Palestinian demonstrators. In addition, Yousry challenges the exclusion of several statements he made to FBI agents.
We review a district court’s evidentiary rulings for abuse of discretion. See United States v. Kelley, 551 F.3d 171, 174 (2d Cir.2009) (per curiam); United States v. Anglin, 169 F.3d 154, 162 (2d Cir.1999). Here, the district court did not abuse its discretion with respect to any such rulings.
We are guided by certain basic principles established by the Federal Rules of Evidence — that, as a general rule, “[a]ll relevant evidence is admissible,” Fed. R.Evid. 402, but that even relevant evidence, although admissible, may be excluded by the district court “if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence,” Fed.R.Evid. 403. “A district court is obviously in the best position to do the balancing mandated by Rule 403.” Salameh, 152 F.3d at 110. “We will second-guess a district court only if there is a clear showing that the court abused its discretion or acted arbitrarily or irrationally.” Id. (internal quotation marks omitted); accord United States v. Szur, 289 F.3d 200, 217 (2d Cir.2002).
Taha’s book was relevant and admissible as evidence of the existence of the Count-Two conspiracy to murder persons in a foreign country. The Bin Laden video was similarly admissible, and relevant to Taha’s intent to murder or kidnap. The district court did not err in failing to find that the evidence was unduly prejudicial.
It was also within the district court’s discretion to exclude both the news video, which it found to be of minimal relevance yet highly prejudicial and confusing, and Yousry’s statements to the FBI, which it found to be essentially duplicative of Yousry’s own testimony.
The district court made a “conscientious assessment of whether unfair prejudice substantially outweigh[ed] probative value,” Salameh, 152 F.3d at 110 (internal quotation marks omitted), and did not otherwise abuse its discretion in making this assessment. We therefore will not disturb its judgments on these grounds.
3. Allegations of Juror Misconduct. It was brought to the district court’s attention after the jury rendered its verdict that a juror, referred to by the parties as “Juror # 39,” had come forward with allegations concerning improprieties during the jury’s deliberations. The defendants requested that the district court “ ‘follow up’ and conduct an inquiry” into these allegations. Sattar IV, 395 F.Supp.2d at 74-78. By written opinion, the district court denied the request. Id. Sattar argues on appeal that the district court’s actions were an abuse of its discretion, insisting that the court should have met, post-verdict, with Juror # 39 to conduct an inquiry. We disagree.
The district court properly construed the request as one for an evidentiary hearing, and concluded that there was no “clear, strong, substantial and incontrovertible evidence ... that a specific, non-speculative impropriety has occurred,” United States v. Ianniello, 866 F.2d 540, 543 (2d Cir.1989), especially in light of the fact that the juror had “several opportunities to communicate directly with the court” regarding any potential improprieties, but failed to do so, Jacobson v. Henderson, 765 F.2d 12, 15 (2d Cir.1985). As the district court explained, “the fact that Juror #39 had direct access to the Court and did not complain of any problems supports the conclusion that these allegations are post hoc efforts caused by *134dissatisfaction that do not require further post-verdict inquiry.” Saltar IV, 395 F.Supp.2d at 77. We agree.
k. Cumulative Error Doctrine. Yousry also argues on appeal that we should reverse under the cumulative error doctrine. But the defendants have not identified any error in the district court’s rulings, “and the accumulation of non-errors does not warrant a new trial.” United States v. Lumpkin, 192 F.3d 280, 290 (2d Cir.1999).
VII. Propriety of the Sentences
The government appeals from the sentences imposed on the defendants, asserting that they are unreasonable and unduly lenient. The government’s principal brief was submitted prior to the Supreme Court’s decisions in Gall v. United States, 552 U.S. 38, 128 S.Ct. 586, 169 L.Ed.2d 445 (2007), and Kimbrough v. United States, 552 U.S. 85, 128 S.Ct. 558, 169 L.Ed.2d 481 (2007), which, as recognized by this Circuit in its en banc decision in United States v. Cavera, 550 F.3d 180 (2d Cir.2008), have significantly altered the landscape of sen-fencing jurisprudence. The Supreme Court issued both Gall and Kimbrough before the government filed its reply brief and oral argument took place, but not before this Circuit had spoken in Cavera.29
A. Standard of Review
The principles that guide our review of the district court’s sentences are, “at first glance, beguilingly simple.” Cavera, 550 F.3d at 188. Generally, we review for abuse of discretion. Id. at 189. That “deferential” scrutiny “encompasses two components: procedural review and substantive review.” Id.
1. Procedural Review. We first determine whether the sentence was procedurally reasonable. See id. Ordinarily, the district court must first correctly calculate the appropriate range set forth by the United States Sentencing Guidelines. Id. at 190. Then it “must form its own view of the nature and circumstances of the offense and the history and characteristics of the defendant,” id. at 188, as mandated and guided by 18 U.S.C. § 3553(a)(1).30 In *135this context, “we review factual findings for clear error and the court’s interpretation of the Sentencing Guidelines de novo.” United States v. Jeffers, 329 F.3d 94, 97 (2d Cir.2003); see also Gall, 128 S.Ct. at 597 (stating that a court procedurally errs when it “select[s] a sentence based on clearly erroneous facts”). In imposing the chosen sentence, the court must “adequately ... explain [that] sentence,” including “any deviation from the Guidelines range.” Cavern, 550 F.3d at 190.
District courts are “generally free to impose sentences outside the recommended [Guidelines] range” but “must consider the extent of the deviation and ensure that the justification is sufficiently compelling to support the degree of the variance.” Id. at 189 (citations and internal quotation marks omitted).
Thus, a district court “must satisfy us that it has ‘considered the parties’ arguments’ and that it has a ‘reasoned basis for exercising [its] own legal decisionmaking authority.’” Id. at 193 (quoting Rita v. United States, 551 U.S. 338, 356, 127 S.Ct. 2456, 168 L.Ed.2d 203 (2007)) (brackets in Cavera). When a court commits “significant procedural error,” we may “remand to the district court so that it can either explain what it was trying to do, or correct its mistake and exercise its discretion anew ... rather than ... proceeding] to review the sentence for substantive reasonableness.” Id. at 190 (citations and internal quotation marks omitted).
2. Substantive Review. Once we are satisfied that a sentence was procedurally proper, we then review the district court’s determination for substantive reasonableness, “tak[ing] into account the totality of the circumstances, giving due deference to the sentencing judge’s exercise of discretion, and bearing in mind the institutional advantages of district courts.”* Id. at 190. Our role is no more than to “patrol the boundaries of reasonableness.” Id. at 191. Indeed, we “must defer heavily to the expertise of district judges,” id. at 193, and will “set aside a district court’s substantive determination only in exceptional cases where the trial court’s decision cannot be located within the range of permissible decisions,” id. at 189 (internal quotation marks and emphasis omitted).
We do not “presume that a non-Guidelines sentence is unreasonable,” nor do we “require ‘extraordinary’ circumstances to justify a deviation from the Guidelines range.” Id. at 190 (quoting Gall, 128 S.Ct. at 595). In evaluating a sentence’s substantive reasonableness, “we may take the degree of variance into account and consider the extent of a deviation from the Guidelines.’ ” Id. We may “consider whether the factor, as explained by the district court, can bear the weight assigned it under the totality of circumstances in the case.” Id. at 191. “[A] major departure should be supported by a more significant justification than a minor one.” Gall, 128 S.Ct. at 597. “But we must not employ a rigid mathematical formula that uses the percentage of a departure as the standard for determining the strength of the justifications required for a specific sentence.” Cavera, 550 F.3d at 190 (internal quotation marks omitted).
Some decisions by the district court may be entitled to more deference than others. For example, as both the Supreme Court and we have noted, variations from the Guidelines “may attract greatest respect when the sentencing judge finds a particu*136lar case outside the heartland to which the Commission intends individual Guidelines to apply.” Kimbrough, 128 S.Ct. at 574-75 (internal quotation marks omitted); accord Cavera, 550 F.3d at 192. When, on the other hand, the variation is based on a general disagreement with the Guidelines’ applicability in a “mine-run case,” then “closer review may be in order.” Kimbrough, 128 S.Ct. at 575.
But such “closer review” is less appropriate where the Guideline in question is not based on empirical data and national history. The issuance of that sort of Guideline “do[es] not exemplify the Commission’s exercise of its characteristic institutional role.” Id. “[A] categorical disagreement with and variance from [such a] Guideline!],” or, at least from the crack cocaine Guidelines, “is not suspect.” Spears v. United States, — U.S. -, 129 S.Ct. 840, 843, 172 L.Ed.2d 596 (2009) (per curiam).
The Supreme Court has yet to address fully the contours of the “respect” that should be afforded to “an ‘inside the heartland’ departure,” id., from Guidelines created by the Commission pursuant to its characteristic institutional role. Such a departure would “necessarily [be] based on a policy disagreement with the Guidelines” and would “necessarily disagree!] [with the Guidelines] on a ‘categorical basis.’ ” Id. We have recognized, however, that “some Guidelines enhancements and reductions apply without modulation to a wide range of conduct.” Cavera, 550 F.3d at 192. Thus, “a district court may find that even after giving weight to the [factors that drive the enhancement or reduction] there is [still] a wide variety of culpability amongst defendants and, as a result, impose different sentences based on the factors identified in § 3553(a).” Id. Of course, irrespective of whether the conduct is found to be inside or outside the “heartland,” the “district court must explain its reasons for its chosen sentence.” Id.31
Affording greater discretion to the district courts may result in greater apparent disparities in sentences. But “the Supreme Court has made clear its view that disparities in sentences imposed by different district judges are more likely to reflect justified differences than are those arising from differences of opinion among appellate panels.” Cavera, 550 F.3d at 193.
B. Application to This Case
The government’s principal claim of error on appeal is that the district court abused its discretion by imposing unreasonably lenient sentences. The government also argues that the district court erred as a matter of law by failing to apply the Guidelines terrorism adjustment, U.S.S.G. § 3A1.4, to Yousry’s offense level.
1. Yousry’s Sentence. The district court initially calculated Yousry’s Guidelines range based on a total offense level of 28 and a criminal history category of I, for a range of 78 to 97 months. According to the government, Yousry’s applicable Guidelines range should have been enhanced in accordance with the terrorism enhancement provided by the Guidelines, U.S.S.G. § 3A1.4. The district court concluded to the contrary that the terrorism enhancement did not apply to Yousry because he did not act with the requisite state of mind. Based on the district *137court’s findings, we agree with its conclusion.
Upon consideration of the various factors set forth in section 3553(a), the district court concluded that a significant downward variance32 was appropriate, and ultimately sentenced Yousry to a non-Guidelines sentence of 20 months of imprisonment, followed by 2 years of supervised release.
a. Guidelines Calculations
We review the district court’s interpretation of the Guidelines de novo, and the district court’s findings of fact for clear error. United States v. Legros, 529 F.3d 470, 474 (2d Cir.2008). We interpret the Guidelines as though they were a statute, giving the words used their common meaning. United States v. Kirvan, 86 F.3d 309, 311 (2d Cir.1996). Section 3A1.4, the so-called “terrorism enhancement,” provides:
(a) If the offense is a felony that involved, or was intended to promote, a federal crime of terrorism, increase by 12 levels; but if the resulting offense level is less than level 32, increase to level 32.
(b) In each such case, the defendant’s criminal history ... shall be Category VI.
U.S.S.G. § 3A1.4. The application notes incorporate 18 U.S.C. § 2332b(g)(5) by reference. See id. cmt. n. 1. That section defines a “Federal crime of terrorism” as:
an offense that—
(A) is calculated to influence or affect the conduct of government by intimidation or coercion, or to retaliate against government conduct; and
(B) is a violation of [any one of many statutes, including 18 U.S.C. § 2339A, relating to the provision of material support to terrorists, and 18 U.S.C. § 956(a)(1), relating to conspiracies to murder persons abroad].
18 U.S.C. § 2332b(g)(5). The conventional meaning of “calculated” is “devised with forethought.” II Oxford English Dictionary 111 (2d ed.1999). Therefore, if a defendant’s purpose in committing an offense is to “influence or affect the conduct of government by intimidation or coercion, or to retaliate against government conduct,” the first requirement of section 2332b(g)(5)(A) is satisfied. If, however, there is no evidence that the defendant “sought to influence or affect the conduct of the government,” the crime is not a federal crime of terrorism. See United States v. Leahy, 169 F.3d 433, 446 (7th Cir.1999).
The enhancement is not limited, however, to offenses that are themselves federal crimes of terrorism. By including the “intended to promote” language, the drafters of the Guideline “unambiguously cast a broader net.” United States v. Mandhai, 375 F.3d 1243, 1247 (11th Cir.2004), cert. denied, 549 U.S. 923, 127 S.Ct. 284, 166 L.Ed.2d 217 (2006). The criminal conduct at issue need not itself meet the statutory definition of a federal crime of terrorism if “a goal or purpose [of the defendant’s act] was to bring or help bring into being a crime listed in 18 U.S.C. 2332b(g)(5)(B).” *138Id. at 1248; accord United States v. Arnaout, 431 F.3d 994, 1001-02 (7th Cir.2005).
The district court declined to apply the terrorism enhancement to Yousry’s sentence. The court explained:
This is a motivational requirement and focuses on the defendant’s purpose. The government has conceded the lack of motivation or purpose and has failed to show that the defendant’s offenses were calculated to influence or affect the conduct of government by intimidation or coercion or to retaliate against government action.
Sent’g Tr. 143-44; see 18 U.S.C. § 2332b(g)(5)(A) (defining “Federal crime of terrorism”). The government does not challenge this finding, which we conclude to be consistent with the record and not clearly erroneous.
Nonetheless, the government argues that the enhancement is appropriate despite the fact that Yousry has committed neither a federal crime of terrorism nor any other crime with the intent to promote such a crime. According to the government, the enhancement applies because Yousry’s offense was “a felony that involved ... a federal crime of terrorism.” U.S.S.G. § 3A1.4 (emphasis added). But under the “involved” prong of section 3A1.4, the enhancement would be applicable to Yousry only if he himself had committed a federal crime of terrorism. See Amaout, 431 F.3d at 1001 (“The ordinary and plain meaning of ‘involved’ means ‘to include.’ ”); United States v. Graham, 275 F.3d 490, 516 (6th Cir.2001), cert. denied, 535 U.S. 1026, 122 S.Ct. 1625, 152 L.Ed.2d 636 (2002) (“[W]e believe that in the context at hand, the word ‘involved’ signifies that a defendant’s offense included a federal crime of terrorism; in other words, that a defendant committed, attempted, or conspired to commit a federal crime of terrorism as defined in 18 U.S.C. § 2332b(g)(5).”). And, as the Fourth Circuit has recognized, commission of a federal crime of terrorism, which would trigger the “involved” prong of the enhancement, incorporates “a specific intent requirement, namely, that the underlying felony was ‘calculated to influence or affect the conduct of government by intimidation or coercion, or to retaliate against government conduct.’ 18 U.S.C. § 2332b(g)(5).” United States v. Chandia, 514 F.3d 365, 376 (4th Cir.2008). So the problem for the government remains: there is no evidence that Yousry himself sought to influence or affect the conduct of a government. The enhancement therefore does not apply under the “involved” prong. See Leahy, 169 F.3d at 446.
The government maintains that any motivational requirement imposed by the terrorism enhancement can be imputed to Yousry from his co-conspirators’ relevant conduct under section IB 1.3(a) of the Guidelines. It provides, in relevant part:
[Adjustments in Chapter Three [including the terrorism enhancement] shall be determined on the basis of the following:
(1)(A) all acts and omissions committed, aided, abetted, counseled, commanded, induced, procured, or willfully caused by the defendant; and
(B) in the case of a jointly undertaken criminal activity (a criminal plan, scheme, endeavor, or enterprise undertaken by the defendant in concert with others, whether or not charged as a conspiracy), all reasonably foreseeable acts and omissions of others in furtherance of the jointly undertaken criminal activity, that occurred during the commission of the offense of conviction, in preparation for that offense, or in the course of attempting to avoid detection or responsibility for that offense....
U.S.S.G. § lB1.3(a). The government asserts that it was reasonably foreseeable to *139Yousry that his co-conspirators were acting in a manner “calculated to influence or affect the conduct of government,” so that the requirement of section 2332b(g)(5)(A) is satisfied as to him.
But sections lB1.3(a)(l)(A) and (B) apply to “acts and omissions,” while, as noted above, section 2332b(g)(5)(A) describes a motivational requirement, a “specific intent.” Ckcmdia, 514 F.3d at 376. We cannot conflate Yousry’s acts with his co-defendants’ mental states. As one member of this Court has pointed out, “We have never regarded mens rea as an ‘act’ of the defendant for purposes of the relevant conduct guideline, nor should we.” United States v. McHugh, 122 F.3d 153, 158 (2d Cir.1997) (Newman, J., concurring). “Section lB1.3(a)(l)(A) permits selection of an enhanced guideline for ‘acts’ committed by the defendant.... The natural meaning of ‘act’ connotes conduct, and the meaning of the guideline should not be strained to include state of mind.” Id. Here, too, the terrorism enhancement’s motivational requirement, as incorporated by reference to section 2332b(g)(5)(A), is not an “act” or “omission” under section lB1.3(a)(l)(B). The enhancement is therefore not applicable.
We have examined the other arguments made by the government in support of its expansive reading of the “involved” prong of the terrorism enhancement and we find them to be similarly without merit.
b. Section 3553(a) Factors
We conclude, then, that the district court properly calculated Yousry’s Guidelines range to be 78 to 97 months. We must therefore determine in light of that range and the totality of the circumstances whether Yousry’s sentence of 20 months of imprisonment, imposed following the district court’s section 3553(a) inquiry, was substantively unreasonable.
We need not outline again the nature of the crimes of which Yousry was convicted. We focus instead on the reasons given by the district court in support of its downward variance.
First, the court found that Yousry’s conduct was “unusual and f[e]ll outside the heartland of material support for terrorist activity.” Sent’g Tr. 150. “[A] district court’s decision to vary from the Guidelines ‘may attract greatest respect when the sentencing judge finds a particular case outside the “heartland” to which the Commission intends individual Guidelines to apply.’ ” Cavera, 550 F.3d at 192 (quoting Kimbrough, 128 S.Ct. at 574-75). We perceive no basis for concluding that the district court erred in deciding that to be the case with respect to Yousry, particularly because he was acting as a translator, not a lawyer or other professional.
Second, the district court found that “no actual harm to victims occurred” although the court was “well aware that such harm is not required and that if such harm occurred the guideline range would be higher.” Sent’g Tr. 150. We conclude that it was not unreasonable for the district judge to decide that the fact that no injury occurred in the case mitigated the gravity of Yousry’s offense.33 The criminal *140law often punishes the substantive commission of a crime more severely than an attempt to commit the same crime, even when that which separates an attempt from the substantive commission of an offense is not culpability but fortuity. Fortuitous events are not categorically irrelevant to the determination of a just punishment nor is their consideration necessarily inappropriate. As the Supreme Court has recently noted, although “[i]t is unusual to impose criminal punishment for the consequences of purely accidental conduct[,] it is not unusual to punish individuals for the unintended consequences of their unlawful acts.” See, e.g., Dean v. United States, — U.S. -, 129 S.Ct. 1849, 1857-58, 173 L.Ed.2d 785 (2009); id. at 1852 (concluding that a defendant who carried a firearm during and in relation to a bank robbery in violation of 18 U.S.C. § 924(c)(1)(A) is subject to a 10 year mandatory minimum pursuant to 18 U.S.C. § 924(c)(l)(A)(iii) because his “firearm [was] discharged” in the course of the robbery, even though “the gun [went] off accidentally,” was not pointed at anyone when it discharged, and nobody was hurt).
Third, the court noted that although Yousry’s offenses were “plainly serious,” his “role in the offenses was subservient to the others involved” in the conspiracy. Sent’g Tr. 150. The Guidelines were “intended to eliminate national disparity,” but “[w]e do not, as a general matter, object to district courts’ consideration of similarities and differences among co-defendants when imposing a sentence.” United States v. Wills, 476 F.3d 103, 109, 110 (2d Cir.2007) (emphasis omitted), abrogated on other grounds by Kimbrough, 128 S.Ct. at 574-75, as recognized in Cavern, 550 F.3d at 191; accord United States v. Williams, 524 F.3d 209, 216 (2d Cir.2008). We also defer to the district court’s conclusion that Yousry’s conduct was less culpable than that of his co-conspirators. On this basis, we conclude that the district court did not err by giving weight to this factor.
Fourth, the district court found that Yousry “did not engage in the offenses for profit and ... did not support or believe in the use of violence to achieve what he wanted.” Sent’g Tr. 150. These facts mitigate the gravity of the conduct at issue. They also affect consideration of the “history and characteristics of the defendant” and the need to “protect the public from further crimes of the defendant” and to “afford adequate deterrence.” 18 U.S.C. § 3553(a). The court concluded that a substantial downward variance was thus justified on the grounds that a lesser degree of punishment than otherwise called for would be sufficient for purposes of deterrence and the protection of the public. As the Gall Court noted, a district court is well-situated to make determinations about the “character of the defendant” and whether, given such a character, the defendant is more or less likely “to return to criminal behavior” or constitute “a danger to society.” Gall, 128 S.Ct. at 600-01.
The district court did not err in finding that Yousry was not motivated by potential profit and did not believe in the use of violence. Nor did it err in considering these factors while fashioning a non-Guidelines sentence for him. In evaluating culpability, we cannot discount the relevance of the defendant’s motivations- — i.e., whether mercenary, see, e.g., 18 U.S.C. § 1958 *141(murder for hire), or born from a commitment to the use of violence. The district court acted well within its discretion in deciding that Yousry was both less dangerous and more easily deterred than had he been acting on a for-hire basis or committed to the use of violence for political ends.
Fifth, the district court found that Yousry’s conviction made it “doubtful that the defendant could pursue” his career as an academic or translator, and therefore that the need for further deterrence and protection of the public is lessened because the conviction itself “already visits substantial punishment on the defendant.” Sent’g Tr. 151. The district court is specifically required by section 3553(a) to consider the “just punishment for the offense.” 18 U.S.C. § 3553(a)(2)(A). It is difficult to see how a court can properly calibrate a “just punishment” if it does not consider the collateral effects of a particular sentence. Upon careful review of the record and the reasons given by the court, we are convinced that the court did so appropriately.
Sixth, the district court found that Yousry provided “extensive ... cooperation” to the government following the terrorist attacks of September 11, 2001. Sent’g Tr. 151. The court concluded that this cooperation “demonstrates a willingness to help law enforcement and reduces the need for rehabilitation and deterrence.” Id. We defer to the district court’s evaluation of the extent of Yousry’s cooperation. And of course, use of a defendant’s cooperation to justify significant variances or departures from the otherwise applicable Guidelines calculations is commonplace. The government argues that Yousry’s assistance was not as extensive as the district court found it to be, but we have been given no cause to question the court’s relevant findings of fact or the manner in which it accounted for them in sentencing.
Seventh, the court found that Yousry “will not be in a situation to commit the offenses of conviction again,” because “it is unlikely that he will ever be able to serve as an interpreter in an official capacity.” Id. We defer to this finding, too. It is not error for a district court to evaluate, based on the defendant’s individual circumstances, the extent of punishment “necessary to deter [him] from engaging in future criminal conduct or to protect the public from his future criminal acts.” Gall, 128 S.Ct. at 602; see 18 U.S.C. § 3553(a)(2)(B) & (C).
The district court did not, of course, assign precise weights to particular factors. Doing so would presuppose “the existence of some ascertainable method of assigning percentages to various justifications,” and would constitute a species of “mathematical approach” which has been expressly disavowed by the Supreme Court as “a classic example of attempting to measure an inventory of apples by counting oranges.” Gall, 128 S.Ct. at 596.
In evaluating the ultimate substantive reasonableness of Yousry’s sentence, we must determine, under the totality of the circumstances, whether these various factors can “bear the weight” assigned to them by the district court. We are satisfied that they can. We are equally satisfied that the district court “considered] the extent of the deviation and ensure[d] that the justification [was] sufficiently compelling to support the degree of variance.” Id. at 597.
In conducting our review, we are further satisfied that the district court did not ignore the Guidelines or “treat them merely as a body of casual advice.” Gavera, 550 F.3d at 189 (internal quotation marks omitted). Even were we inclined to think that the district court did not appreciate the weight of the Guidelines — which, as we say, we are not — in light of all of the *142foregoing, including the court’s long-term and intimate involvement with these proceedings, any such conclusion would be purely a matter of surmise on our part. See Rita, 551 U.S. at 357-58, 127 S.Ct. 2456 (noting that the sentencing judge had “greater familiarity with[] the individual case and the individual defendant before him than the Commission or the appeals court”); see also Gall, 128 S.Ct. at 597. The district court did not abuse its discretion in sentencing Yousry.
2. Sattar’s Sentence. The district court calculated Sattar’s total offense level to be 43 and his criminal history category to be VI, for a Guidelines “range” of life imprisonment. But in conducting its own independent review, as guided by section 3553(a), the district court concluded that such a sentence would be “seriously disproportionate” to the offense. Sent’g Tr. 35. The court imposed a sentence of 24 years (288 months) of imprisonment, to be followed by five years of supervised release.
a. Guidelines Calculation
The district court calculated Sattar’s sentence, as it did Yousry’s, under the November 2000 Guidelines. The court ultimately adopted the recommendations of the Probation Department in making its Guidelines calculation, except insofar as the district court added enhancements based on Sattar’s obstruction of justice.
i. Enhancements. Sattar’s Guidelines “range” of life imprisonment was arrived at based in part on the sentencing court’s determination that the terrorism enhancement applied to both Sattar’s Count-Two and Count-One conduct. The district court also enhanced Sattar’s sentence on the ground that he obstructed justice. See U.S.S.G. § 3C1.1.
ii. Departures. Sattar moved for a downward departure based on the conditions of his confinement. The district court recognized that it was able to depart under the Guidelines for severe conditions of detention, but “because thus far th[ose conditions] reflect only strict security measures rather than an abuse of those measures,” it declined to do so. Sent’g Tr. 33. Instead, the court concluded that it would take Sattar’s conditions of confinement into account in considering the section 3553(a) factors.
b. Section 3553(a) Factors
The district court began its section 3553(a) analysis with a correct calculation of the applicable Guidelines “range” — life imprisonment. The court then imposed the non-Guidelines sentence of 24 years’ imprisonment, for which it gave three principal reasons.
First, the court concluded that the terrorism enhancement overstated the seriousness of Sattar’s crime by. transforming a Guidelines range of 97 to 121 months to life imprisonment. The court found that the otherwise-applicable Guideline range was “relatively low” because Sattar was convicted of conspiracy to murder and not of murder itself, and that the terrorism enhancement failed to account for the fact that “no injury actually occurred in this case.” Sent’g Tr. 35. The district court noted that a variance downward from a Guidelines range driven upward by the enhancement is permissible when the enhancement “prevents the penalty from fitting the crime, based on the facts of th[e] record.” Id. at 35-36 (citing Mandhai, 375 F.3d at 1249).
Second, the terrorism enhancement put Sattar in the highest criminal history category, VI, “without a single past criminal history point.” Id. at 36. The district court concluded that such a jump “overstates [Sattar’s] past conduct and the like*143lihood that the defendant after a substantial period of incarceration would commit further crimes.” Id.
Third, the court noted that Sattar had been under “extremely restrictive conditions of confinement for 4-1/2 years,” and there “is every reason to expect that his conditions of confinement will continue to be substantially more severe than the average prisoner.” Id. at 37. These conditions include being kept in a cell for 23 hours a day and under constant surveillance. As a result, the court concluded, “the punitive aspects of the defendant’s confinement are increased and the deterrent effect of the defendant’s confinement is also increased.” Id.
The court further noted that, for reasons explained in part under seal, a downward variance is warranted based on factors relevant to the history and characteristics of the defendant and the need to afford adequate deterrence.34 The district court observed that based on the totality of the circumstances and on its review of cases presented by the government as comparators, Sattar’s sentence of 24 years’ incarceration does not promote unwarranted sentencing disparities.
c. Analysis
The government’s principal argument on cross-appeal is that Sattar’s sentence is substantively unreasonable in light of his conduct and “long-term dedication to violence.” Gov’t Reply Br. 39. We have no quarrel with the government as to the nature and quality of Sattar’s conduct. Neither, to any significant extent, did the district court. It considered, at length, the seriousness of Sattar’s crimes.
“[A] sentence outside the Guidelines carries no presumption of unreasonableness.” Irizarry v. United States, 553 U.S. 708, 128 S.Ct. 2198, 2202, 171 L.Ed.2d 28 (2008). “[T]he Guidelines are only one of the factors to consider when imposing sentence. ...” Gall, 128 S.Ct. at 602. Taking those precepts as a starting point, we are satisfied that in fashioning a non-GuideIines sentence, the district court did not clearly err in according weight to the factors it identified. As we recently noted in Cavera, “at the procedural part of review, we will not categorically proscribe any factor ‘concerning the background, character, and conduct’ of the defendant, with the exception of invidious factors.” Cavera, 550 F.3d at 191. The object is always to fashion a sentence “sufficient, but not greater than necessary” to accomplish the purposes set forth in 18 U.S.C. 3553(a). And it was not clear error for the district court to conclude that a criminal history category of VI significantly overstated Sat-tar’s criminal history and likelihood of committing further offenses.
We have recognized that “the Sentencing Commission had a rational basis for creating a uniform criminal history category for all terrorists under [U.S.S.G.] § 3A1.4(b), because even terrorists with no prior criminal behavior are unique among criminals in the likelihood of recidivism, the difficulty of rehabilitation, and the need for incapacitation.” United States v. Meskini, 319 F.3d 88, 92 (2d Cir.), cert. denied, 538 U.S. 1068, 123 S.Ct. 2240, 155 L.Ed.2d 1125 (2003). But in the same virtual breath, we said, “[a] judge determining that § 3A1.4(b) over-represents ‘the seriousness of the defendant’s past criminal conduct or the likelihood that the defendant will commit other crimes’ always *144has the discretion under § 4A1.3 to depart downward in sentencing. U.S.S.G. § 4A1.3.” Id.
And even with enhancements of magnitude — i.e., those that “sharply increase the recommended sentences” — there still may be “a wide variety of culpability amongst defendants.” Cavern, 550 F.3d at 192. There may therefore be “different sentences based on the factors identified in § 3553(a).” Id. Sattar’s crimes are indeed grave; he may well be the most culpable of these defendants. But the district court has a responsibility, inter alia, “to avoid unwarranted sentence disparities among defendants with similar records who have been found guilty of similar conduct,” 18 U.S.C. § 3553(a)(6). Perhaps all who merit this enhancement are culpable and dangerous — but some among them are more culpable, more dangerous, with crimes more serious, than others. It is the district court that is primarily charged with the responsibility for making such distinctions.
The district court is also in the best position to make an individual determination about the “history and characteristics” of a particular defendant, and to adjust the individualized sentence accordingly. See 18 U.S.C. § 3553(a); cf. U.S.S.G. § 4A1.3 (permitting downward departure where “the court concludes that a defendant’s criminal history category significantly over-represents the seriousness of a defendant’s criminal history or the likelihood that the defendant will commit further crimes”). Upon examining the reasons the district court gave, we have no reason not to defer to its assessment here.
It was not unreasonable for the district court to conclude that the severity of the conditions of confinement would increase the severity of the punishment and the amount of deterrence associated with a given term of imprisonment in light of the particular conditions of confinement under which Sattar is incarcerated. The district court did not abuse its discretion in varying downward based on those conditions here. We think that the factors upon which the district court relied in determining Sattar’s appropriate sentence can “bear the weight” the district court assigned to them. Cavera, 550 F.3d at 191.
We note, finally, that the court sentenced Sattar to more than twice what the maximum Guideline sentence would have been without the terrorism enhancement.
The sentence thus adequately reflected the severity of the crime.
3. Stewart’s Sentence. Befox-e sentencing Stewart, the district court calculated her offense level under the November 2000 Guidelines to be 41, her cxdminal history category to be VI, and her Guidelines range to be 360 months, or 30 years, the statutory maximum. The court concluded, however, that a sentence of 28 months’ imprisonment was sufficient but no greater than necessary to accomplish the purposes set forth in 18 U.S.C. § 3553(a).
a. Guidelines Calculations
i. Enhancements. Over Stewart’s objection, the district coxxrt concluded that the terrorism enhancement of section 3A1.4 applied because she had committed a federal crime of terrorism. The enhancement was triggered in part by the district court’s finding that Stewart’s actions were “calculated to affect the conduct of the Egyptian government through intimidation and coercion.” Sent’g Tr. 108. The district court noted that Stewart’s “conduct cannot be found to be outside the heartland of the enhancement,” but stated that it nonetheless would “take all of the defendant’s arguments [as to why the enhancement did not properly apply to her *145conduct] into account in performing the analysis under Section 3553(a).” Id.
The district court noted that the terrorism enhancement automatically placed Stewart in criminal history category VI. The court appeared to accept Stewart’s argument that the enhancement overstated the seriousness of her past conduct or the likelihood that she would commit further crimes. Instead of adjusting the criminal history in the context of the Guidelines calculations themselves, however, the court found this to be “one of the rare cases” under United States v. Crosby, 397 F.3d 103, 112 (2d Cir.2005), where it would be more appropriate to determine the extent of the downward adjustment in the context of the section 3553(a) analysis. Sent’g Tr. 109.35
The government also sought an enhancement of Stewart’s sentence on the ground that she obstructed justice. The Guidelines provide that where a defendant “willfully obstructed or impeded, or attempted to obstruct or impede, the administration of justice with respect to the investigation, prosecution, or sentencing of the instant offense of conviction” and where the obstructive conduct related to the offense of conviction or a closely related offense, that the applicable Guidelines should be enhanced by 2 levels. U.S.S.G. § 3C1.1. The government argued that Stewart committed perjury by testifying “that she understood that there was a bubble built into the SAMs whereby the attorneys could issue press releases containing Abdel Rahman’s statements as part of their representation of him” and testifying about her purported lack of knowledge of Taha. Sent’g Tr. 111. As we have noted, Taha was a follower of Abdel Rahman and a military leader in al-Gama’a who claimed responsibility for the November 1997 massacre at Luxor, and was allegedly part of the CounL-Two conspiracy. The district court noted that there was “evidence to indicate that [Stewart’s] statements were false statements.” Id. It concluded, however, that it was “unnecessary to reach [the question] whether the defendant knowingly gave false testimony with the intent to obstruct the proceedings” for two reasons: First, the Guidelines calculation already provided for the statutory maximum permitted by the statutes of conviction, and second, a non-Guidelines sentence was, in the estimation of the court, “reasonable and most consistent with the factors set forth in Section 3553(a).” Id. at 111-12.
ii Departures. Stewart sought a downward departure pursuant to section 5H1.4 of the Guidelines, which provides that while “[p]hysical condition ... is not ordinarily relevant in determining whether a sentence should be outside the applicable guideline range,” nonetheless “an extraordinary physical impairment may be a reason to impose a sentence below the applicable guideline range.” U.S.S.G. § 5H1.4. Stewart proffered substantial documentation of serious illness. As with Stewart’s criminal history calculations, the district court concluded that it “[did] not have to reach the question of whether [Stewart’s] medical condition, given her age and continuing treatment, is sufficient in itself to warrant a departure from the guidelines,” because it would take that condition into *146account in making its determination under section 3553(a). Sent’g Tr. 110.
The district court declined to adjust the Guidelines calculations based on Stewart’s argument that she committed her crime in order to avoid a perceived greater harm as set forth in “Lesser Harms” policy statement of the Guidelines. See U.S.S.G. § 5K2.11. Stewart argued before the district court that her conduct “was the product of her perception that her client’s health and well-being [were] seriously jeopardized by his continued imprisonment in the United States.” Stewart Sent’g Br. 44-45. Under the policy statement, where a defendant “commitfs] a crime in order to avoid a perceived greater harm,” “a reduced sentence may be appropriate, provided that the circumstances significantly diminish society’s interest in punishing the conduct, for example, in the case of a mercy killing.” U.S.S.G. § 5K2.11. However, “[w]here the interest in punishment or deterrence is not reduced, a reduction in sentence is not warranted.” Id. Here, the district court found this case not to be one where the interest in punishment or deterrence is reduced.
The policy statement further provides that a reduction in the otherwise applicable sentence might be appropriate where “conduct may not cause or threaten the harm or evil sought to be prevented by the law proscribing the offense at issue” such as “where a war veteran possessed a machine gun or grenade as a trophy, or a school teacher possessed controlled substances for display in a drug education program.” U.S.S.G. § 5K2.11. But the court declined to conclude that Stewart’s conduct did not cause or threaten the harm sought to be prevented by the statutes that Stewart violated.
Stewart also moved for a departure on the ground that her conduct was “aberrational.” A Guidelines policy statement provides that “[a] sentence below the applicable guideline range may be warranted in an extraordinary case if the defendant’s criminal conduct constituted aberrant behavior.” U.S.S.G. § 5K2.20. But the court, noting that Stewart’s conduct was “committed over an extended period of time, involv[ing] repeated acts of deception, and ... significant planning,” Sent’g Tr. 110, concluded that such a departure would be inappropriate, and declined to grant it.
The district court thus reached its final Guidelines calculation, using the November 2000 Guidelines, with a total offense level of 41, a criminal history category of VI, and therefore a Guidelines “range” of 360 months, the statutory maximum. The government sought a term of life imprisonment; Stewart sought a non-incarceratory sentence.
b. Section 3553(a) Factors
Based on its section 3553(a) analysis, the district court’s sentence substantially varied from the applicable Guidelines range.
As the starting point for its section 3553(a) analysis, the court addressed the applicability of the terrorism enhancement, which “while correct under the guidelines, would result in an unreasonable result ... and produce a guideline range about quadruple the range [that would otherwise apply] without the enhancement.” Sent’g Tr. 114. The district court then observed:
First, that Stewart’s was an “atypical case” for the terrorism enhancement inasmuch as “the thrust of the violation was the provision of a co-conspirator to a terrorist conspiracy,” id. at 113; second, as with Sattar, that the structure of the terrorism enhancement prevented the Guidelines from taking into account the fact that no victim was harmed as a result of the offense as charged; and third, again as with Sattar, that the enhancement operat*147ed to prevent the Guidelines from taking into account Stewart’s actual criminal history. By virtue of the terrorism enhancement, Stewart was automatically classified as within criminal history category VI, the highest possible category, whereas if her sentence were based on her actual criminal history, she would have been classified in category I, the lowest possible category.
The court therefore concluded that the terrorism enhancement was “dramatically unreasonable” and “overstates the seriousness of [her] past conduct and the likelihood that [she] will repeat the offense.” Id. Stewart “has no criminal history and yet is placed in the highest criminal history category equal to that of repeat felony offenders for the most serious offenses including murder and drug trafficking.” Id. at 113-14. The criminal history category was inappropriate, the court determined, in light of “the likelihood of recidivism, the difficulty of rehabilitation and the need for incapacitation.” Id. at 114.
The court found that Stewart’s opportunity to repeat “the crimes to which she had been convicted will be nil” because she “will lose her license to practice law” and “will be forever separated from any contact with Sheikh Omar Abdel Rahman.” Id. Loss of her license to practice law both removes “the occasion for her offenses” and “is itself a punishment.” Id. at 116.
The district court viewed Stewart’s personal characteristics as “extraordinary” and thought they “argue[d] strongly in favor of a substantial downward variance.” Id. at 114. The court described her as a dedicated public servant who had, throughout her career, “represented the poor, the disadvantaged and the unpopular, often as a Court-appointed attorney,” thereby providing a “service not only to her clients but to the nation.” Id. at 115-16. And “[h]aving spent her professional career often representing the poor, she is now, at the end of her career, financially destitute.” Id. at 115.
The court also took into account Stewart’s ill health — she had, for example, suffered from cancer, for which she had undergone surgery and radiation therapy, and for which there is a significant chance of recurrence. The district court was of the view that in light of those conditions and her age, 67 years old at the time, prison would be “particularly difficult” for her, and that at her age, moreover, her sentence would “represent a greater portion of her remaining life than for a younger defendant and provide increased punishment.” Id. at 117.
c. Analysis
i. The Scope of Review. The government’s principal argument on appeal is that in light of the crimes of which Stewart stands convicted, her sentence was substantively unreasonable. Section 3553(a) instructs that the sentence must “reflect the seriousness of the offense, ... promote respect for the law, and ... provide just punishment for the offense” and “afford adequate deterrence to criminal conduct.” 18 U.S.C. § 3553(a)(2)(A) & (B). Our review for substantive reasonableness is a “particularly deferential form of abuse-of-discretion review.” Cavera, 550 F.3d at 188 n. 5 (citing Gall 128 S.Ct. at 591). But our review must also be “meaningful.” Gall, 128 S.Ct. at 597; cf. Gerard E. Lynch, Letting Guidelines Be Guidelines (And Judges Be Judges), Ohio St. J.Crim. L. Amici: Views From the Field (Jan. 2008), at http://osjcl.blogspot.com/ (“[W]e should let (appellate) judges be judges ..., performing their traditional function of reining in excess and gradually developing a ‘common law’ of what is and is not sensible.” (emphasis deleted)).
Like the district court, we are impressed by the factors that figured in Stewart’s *148modest sentence — particularly her admirable history of providing, at no little personal cost to herself, proficient legal services in difficult cases to those who could not otherwise afford them. We think it noteworthy, moreover, that the last of the acts for which Stewart is being punished occurred a short time before the September 11 attacks on the United States. That carnage might have raised in her, as it surely has in many or most of us, a heightened awareness of and sensitivity to the imminent dangers of terrorism and the possible scope of the deadly capabilities of the terrorists with whom she was dealing.
We also recognize, as did the district court, that the terrorism enhancement may apply to persons who are culpable in substantially different degrees; that Stewart’s culpability may well be understood to be less than Sattar’s; and that the district court may differentiate between different levels of culpable conduct that nonetheless trigger the same substantial enhancement. Yet Stewart’s sentence is strikingly low in light of what the district court correctly described as the “irreducible core of [her] extraordinarily severe criminal conduct,” Sent’g Tr. 118, “which was committed over an extended period of time, involved repeated acts of deception, and involve[d] significant planning,” id. at 110.
We are obliged to “patrol the boundaries of [the] reasonableness” of a sentence. Cavera, 550 F.3d at 191. While we will not lightly deem unreasonable a sentence imposed by the judge who has “access to, and greater familiarity with, the individual case and the individual defendant before him than the [Sentencing] Commission or the appeals court,” Rita, 551 U.S. at 357-58, 127 S.Ct. 2456, we think that in light of the fact Stewart used her privileged status as a lawyer to facilitate her serious violation of the law, and possibly committed perjury at trial in an attempt to avoid punishment for her conduct, her sentence at least tests those “boundaries.”
ii. Stewart’s Abuse of Her Status As a Member of the Bar. Stewart argues that she did no more than serve as a zealous advocate for her client. That belief, if indeed she harbored it, gave her no license to violate the law. Stewart’s actions tended ultimately and ironically to subvert the same fundamental right of which she took advantage — the constitutional right to counsel — by making it less likely that other incarcerated persons will have the same level of access to counsel that her client was given.
The district court seemed to appreciate that fact, noting that Stewart “abused her position as a lawyer” in committing her crimes. Sent’g Tr. 118. The court did not, however, explain how and to what extent the sentence reflected the seriousness of the crimes of conviction in light of the fact that Stewart was engaged as a member of the bar when she committed them.
The question therefore remains whether, because she was an experienced and dedicated lawyer acting as such when she broke the law in the manner that she did, her punishment should have been greater than it was.36
*149in. A Comparison of Yousry’s and Stewart’s Sentences. A comparison of Stewart’s and Yousry’s offense conduct serves to highlight the seriousness of Stewart’s crimes and the seemingly modest sentence she received for it. Unlike Yousry, Stewart publicly disseminated “potentially lethal” statements on Abdel Rah-man’s behalf. Unlike Yousry, Stewart was convicted of making false statements to the government when she agreed to abide by the terms of the SAMs. Unlike Yousry, Stewart was a member of the bar and therefore acting as an officer of the court. See, e.g., United States v. Seltzer, 227 F.3d 36, 41 (2d Cir.2000). She was legally knowledgeable, highly experienced, and politically sophisticated, a lawyer acting in her professional capacity; he was a student working for her and Abdel Rahman as a translator.
Yet Yousry’s sentence was 20 months; Stewart’s only eight months longer.
iv. Steivart’s Alleged Perjury. Also unlike Yousry, Stewart may well have obstructed justice at trial. The government, supported by substantial evidence, argued that Stewart committed perjury at trial. The district court summarized the argument as follows:
First, the government contends that Ms. Stewart knowingly gave false testimony when she testified that she understood that there was a bubble built into the SAMs whereby the attorneys could issue press releases containing Abdel Rah-man’s statements as part of their representation of him.
The government also contends that Ms. Stewart testified falsely when she denied knowing who Taha was until learning about him in the course of the trial except for an article that she came across in her representation of Yasir Ahmed.
Sent’g Tr. 111. The court, having thus recited the allegations at sentencing, declined to decide the issue.
As noted, the district court gave two reasons for not making such a finding. First, it concluded that because Stewart’s Guidelines calculations had reached the statutory maximum of 360 months, a finding of obstruction of justice would not have changed the calculation. This would be true if the terrorism enhancement had been applied in Stewart’s case, but the district court, after determining that Stewart’s conduct was in the enhancement’s “heartland,” may not have applied it. See infra 150-51. And even were it true, the question of Stewart’s perjury is nonetheless relevant to her sentence pursuant to section 3553. Section 3553(a) requires the district court to impose a sentence “sufficient, but not greater than necessary” to, among other things, promote respect for the law. See 18 U.S.C. § 3553(a)(2). Whether Stewart lied to the jury under oath or upon affirmation at her trial is relevant to whether her sentence was “sufficient” under the circumstances.
The district court’s second reason for declining to determine whether Stewart committed perjury during the course of her testimony was that it had determined that a non-Guidelines sentence was “reasonable and most consistent with the factors set forth in Section 3553(a).” Sent’g Tr. 111-12. But as noted, we think that whether Stewart lied under oath at her trial is directly relevant to whether her *150sentence was appropriate in light of Section 3553(a). Her willingness as a lawyer knowingly and falsely to affirm her intention to obey the SAMs and then to seek to cover up this knowing violation of the law with perjurious testimony might well, if proven, influence our conclusion as to the propriety of her sentence. Any cover-up or attempt to evade responsibility by a failure to tell the truth upon oath or affirmation at her trial would compound the gravity of her crime.
We conclude that by declining to decide whether Stewart committed perjury or otherwise obstructed justice, the district court procedurally erred.
v. Effect of Lack of Harm. Noting particularly that the absence of harm was fortuitous and not the result of efforts by Stewart to prevent harm, Judge Walker argues that it was error both procedural and substantive for the district court to use that factor as a basis for downward variance, especially such a large one. The issue is discussed also in Judge Calabresi’s opinion. This Court makes no ruling on that issue now, in the circumstances of Stewart’s case. We note simply that it is a serious issue to be given consideration by the district court upon reevaluating Stewart’s sentence. In view of the fact that the court must resentence, we think it preferable to defer this issue until after it has been reconsidered by the court, upon its consideration of the commentary in the opinions of Judges Walker and Calabresi.
vi. The Terrorism Enhancement. The terrorism enhancement is set forth in section 3A1.4 of the Guidelines. Terrorism
(a) If the offense is a felony that involved, or was intended to promote, a federal crime of terrorism, increase by 12 levels; but if the resulting offense level is less than level 32, increase to level 32.
(b) In each such case, the defendant’s criminal history category from Chapter Four (Criminal History and Criminal Livelihood) shall be Category VI.
U.S.S.G. § 3A1.4.
Whether or not the district court applied the terrorism enhancement to Stewart in its Guidelines calculation may be subject to disagreement. Without reaching that issue, we nonetheless note that in light of the facts of this case and the judgments of conviction, which we affirm, the terrorism enhancement plainly applies as a matter of law to the district court’s calculation of the applicable Guidelines range, irrespective of whether Stewart’s behavior was “atypical” and whether it resulted in death or injury,37 factors that may (or may not) be *151employed in rendering the ultimate sentence.
Whether or not the district court gave appropriate consideration in its section 3553(a) analysis to whether support of terrorism is an aggravating factor in this case, similarly, may be subject to disagreement. Judge Walker argues that the district court’s sentence was deficient in this respect, and constituted both procedural and substantive error. But we need not decide whether error in this respect, if any, would be procedural or substantive. Without reaching these issues, and without suggesting that the district court was bound to follow either the Guidelines generally or any Guidelines enhancement specifically in imposing its section 3553(a) sentence, we note that the district court’s section 3553(a) analysis must include consideration of whether support of terrorism is an aggravating factor in light of the court's obligation to consider “the nature and circumstances of [Stewart’s] offense” and “the need for the sentence imposed ... to reflect the seriousness of the offense.” 18 U.S.C. § 3553(a)(l)-(2)(A).
d. Remand
A district court’s failure to find particular facts will in no way impede our review in some, perhaps in most, situations; this, however, is not one of them. Especially in light of the absence of a finding that Stewart did not commit perjury at trial or otherwise obstruct justice, we think it preferable not to determine whether her sentence was substantively reasonable.
We therefore remand this matter to the district court for resentencing, in the course of which we direct the court to determine the issue of perjury and if it finds such perjury, to resentence Stewart so as to reflect that finding. The district court should also consider whether Stewart’s conduct as a lawyer triggers the special-skill/abuse-of-trust enhancement under the Guidelines, see U.S.S.G. § 3B1.3, and reconsider the extent to which Stewart’s status as a lawyer affects the appropriate sentence. Finally, the district court should further consider the overall question whether the sentence to be given is appropriate in view of the magnitude of the offense, which the court itself has explicitly recognized. Although we do not preclude the district court’s election to continue to impose a non-Guidelines sentence, we do require that such a sentence, selected after the reconsideration we have directed, begin with the terrorism enhancement and take that enhancement into account. We have serious doubts that the sentence given was reasonable, but think it appropriate to hear from the district court further before deciding the issue.
We have identified actions taken or not taken by the district court in imposing sentence that we conclude constituted procedural error and thus require resentencing. Other issues are raised by Judge Walker, who finds that they resulted in procedural error and substantive unreasonableness, and addressed by Judge Calabresi in response. To the extent we did not discuss or rule on those issues in this majority opinion, our silence should not be construed by the district court, or by others relying on this opinion, to mean that the majority has adopted Judge Calabresi’s views or rejected Judge Walker’s. We have not.
Although we find no procedural or substantive error in connection with the sen*152teneing of Sattar and Yousry, we nonetheless remand their cases, too. We conclude that, inasmuch as the interrelationship among the sentences of the co-defendants is a principal consideration as to a proper sentence of Stewart, the district court should have the ability, if not the obligation, to resentence them as well.
After the district court completes the resentencing, jurisdiction may be restored to this Court by letter from any party, and the Office of the Clerk of this Court shall set an expeditious briefing schedule and refer the matter to this panel for further review.
CONCLUSION
For the foregoing reasons, we affirm the conviction of Stewart, but remand this cause to the district court for resentencing of Stewart, see United States v. Phillips, 431 F.3d 86, 90 (2d Cir.2005), and resentencing of Sattar or Yousry or both if the district court determines that they should receive different sentences in light of the sentence imposed on Stewart. Inasmuch as the current sentences will remain in effect as to Stewart and Yousry until the district court resentenees Stewart — and Sattar or Yousry if it decides to do so— and in light of the fact that we affirm on all issues related to the guilt of all defendants, the district court is directed to order Stewart and Yousry to surrender forthwith to begin serving their terms of incarceration.