Unpublished opinions are not binding precedent in this circuit.

DAVIS, Circuit Judge

Mohamad Youssef Hammoud ("Hammoud") was convicted of fourteen offenses following a jury trial.1 He was sentenced under the then-mandatory Sentencing Guidelines to 155 years' imprisonment. After we affirmed the convictions and sentence, see United States v. Hammoud, 381 F.3d 316 (4th Cir. 2004) (en banc), the Supreme Court vacated and remanded in light of United States v. Booker, 543 U.S. 220 (2005), see Hammoud v. United States, 543 U.S. 1097 (2005). On remand, we reinstated the portions of our prior opinion resolving Hammoud's challenges to his convictions and the calculation of the guidelines range and remanded for resentencing. See United States v. Hammoud, 405 F.3d 1034 (4th Cir. 2005). The district court conducted a resentencing hearing and granted a variance sentence of 30 years' imprisonment. Both parties appeal, challenging among other things the reasonableness of the sentence imposed. We affirm.

I.

In Hammoud's earlier appeal, we laid out the "largely undisputed" facts underlying this prosecution, which are unnecessary to repeat in any detail here. See Hammoud, 381 F.3d at 325-27. In that opinion, we rejected, inter alia, Hammoud's challenges to his convictions for providing, and conspiring to provide, material support to a DFTO and to the district court's application of U.S.S.G. § 3A1.4, the terrorism enhancement. We rejected Hammoud's contention that the preponderance standard should not apply to the application of § 3A1.4 because it "is `a tail which wags the dog of the substantive offense.'" Id. at 354-55 (quoting McMillan v. Pennsylvania, 477 U.S. 79, 88 (1986)).

We also rejected his contentions that the district court should have applied U.S.S.G. § 2M5.3, the guideline applicable to violations of 18 U.S.C. § 2339B, and should not have applied § 3A1.4. Id. at 355-56. We stated, "Even assuming that the district court should have applied § 2M5.3, there was no error." Id. at 355 (footnote omitted). We held that "a defendant who has been convicted of providing material support to [a DFTO] may be subject to the enhancement if the evidence establishes that he provided such support with the intent to influence or coerce government conduct," that the application of § 3A1.4 did not result in impermissible "double counting," and that the evidence presented at trial was sufficient to support application of the enhancement. Id. at 355-56. We affirmed the judgment of the district court in its entirety. Id. at 357.

Hammoud's base offense level was 46 (treated as 43, see U.S.S.G. Ch.5, Pt.A, cmt. n.2) and his criminal history category ("CHC") was VI. Id. at 327. "Because none of the offenses of conviction carried a statutory maximum of life imprisonment," for which the guidelines provided, "the district court imposed the maximum sentence on each count and ordered all sentences to be served consecutively." Id. (citing U.S.S.G. § 5G1.2(d)). We thus consider 155 years' imprisonment to be Hammoud's "advisory Guidelines range" for purposes of considering the extent of the variance. See United States v. Sarras, 575 F.3d 1191, 1208-09, 1219 (11th Cir. 2009) ("Because the statutory maximum was less than the total guidelines punishment of life imprisonment, § 5G1.2(d) of the guidelines called for the sentences for multiple counts to run consecutively as the advisory guidelines sentence.") (emphasis added).

After the Supreme Court vacated our decision and remanded for reconsideration in light of Booker, we reinstated the portions of our opinion resolving Hammoud's objections to his convictions and the calculation of his guidelines range, including the portion rejecting Hammoud's challenge to the terrorism enhancement. See Hammoud, 405 F.3d 1034. We remanded for resentencing under the advisory guidelines regime.

On remand, the district court declined to revisit its calculation of the guidelines or to consider any potential departures; instead, it limited resentencing to consideration of a potential variance under 18 U.S.C. § 3553(a). During resentencing, Hammoud introduced new evidence he urges that discredits the trial evidence on which the district court had relied when it imposed the original sentence, see Hammoud's Br. 15, including testimony from Robert Baer, a Hizballah expert and former CIA agent; Theresa Finocchio, a former business partner who also had a personal relationship with a witness who testified against Hammoud at trial; Lara Deeb, Ph.D., a professor who submitted a sworn statement introduced at the resentencing hearing with respect to Sayyid Fadlallah; and Sheikh Abbas Harake, an operational commander for Hizballah who submitted an affidavit introduced at the resentencing hearing. Hammoud also submitted a "compilation of approximately 168 cases involving material support of a DFTO, financial material support, and virtually every other terrorism related case the Defense could find, including every reported U.S.S.G. §3A1.4 case." Id. at 27 (citing J.A. 5675-5778).

In response to the district court's request to provide evidence to refute Harake's affidavit, the Government presented evidence from FBI Special Agent David Yu, who testified under restriction that "Israeli Intelligence confirms that according to a reliable source Harake Abbas is a Hezbollah operational commander." J.A. 4758. Hammoud was given an opportunity to cross-examine the agent, but the district court did not require the agent to reveal "sources and methods" by which the information was provided. J.A. 4761, 4765. The Government thereafter submitted an affidavit from another FBI Special Agent confirming the same.

At the continued resentencing hearing, the district court heard from counsel as to what they believed to be an appropriate sentence and gave Hammoud a chance to allocute. The district court then imposed sentence. The district court explained that it was bound by the guidelines calculation, that it would consider the § 3553(a) factors as applied to Hammoud and that it would justify the chosen sentence to allow for meaningful appellate review. The district court then recited the facts it deemed most relevant to its decision, carefully examined the § 3553(a) factors and imposed a sentence of 30 years' imprisonment.

II.

On appeal, Hammoud challenges the district court's application of the mandate rule, the admission of certain evidence at resentencing, and, ultimately, the reasonableness of the sentence imposed.2 The Government cross-appeals, challenging the district court's sentence as substantively unreasonable. Upon our careful review of the entire record, we discern no error; accordingly, we affirm the judgment of the district court.

A.

Hammoud first argues that the mandate rule was misapplied and that this case falls within each of the exceptions to the mandate rule. Applying de novo review, we easily reject this contention. See Doe v. Chao, 511 F.3d 461, 464 (4th Cir. 2007) ("We review de novo whether a post-mandate judgment of the district court `contravenes the mandate rule, or whether the mandate has been "scrupulously and fully carried out."'").

Generally, a lower court is "bound to carry the mandate of the upper court into execution and may not consider the questions which the mandate laid at rest." United States v. Bell, 5 F.3d 64, 66 (4th Cir. 1993) (internal quotation marks and brackets omitted). The mandate rule "compels compliance on remand with the dictates of a superior court and forecloses relitigation of issues expressly or impliedly decided by the appellate court" and "litigation of issues decided by the district court but foregone on appeal or otherwise waived." Id.3 The mandate rule does not apply where (1) there has been a "showing that controlling legal authority has changed dramatically"; (2) "significant new evidence, not earlier obtainable in the exercise of due diligence has come to light"; or (3) "a blatant error in the prior decision will, if uncorrected, result in a serious injustice." Id. at 67 (internal quotation marks and brackets omitted).

It is clear that when we reinstated the portions of our prior opinion resolving the calculation of Hammoud's guidelines range, most notably rejecting Hammoud's attacks on the standard of proof with respect to and application of the terrorism enhancement, we effectively limited resentencing to consideration of a variance sentence. See Hammoud, 405 F.3d 1034. Furthermore, none of the exceptions to the mandate rule apply here.

The Supreme Court decisions cited by Hammoud have not changed the law regarding the computation of his (now advisory) guidelines range. Nor, as Hammoud argues, was it impossible for the district court to address freshly the variance issue given the change in the law. In other words, the district court could be bound by our affirmance of the guidelines calculation and adequately exercise its discretion to vary downward, if it thought a variance was warranted, in considering the newly presented evidence and the arguments of the parties.

Hammoud has likewise failed to demonstrate how the evidence he introduced at resentencing was originally unavailable in the exercise of due diligence. We find unavailing, as clarified at oral argument, that the historical context made certain evidence that "attacks directly the First PSR's conclusions," Hammoud's Br. 52, unavailable because it left counsel unable to find an expert who would testify in favor of Hammoud on the material support issue. Similarly, we find unavailing Hammoud's argument that impeachment evidence relevant to two witnesses who testified against Hammoud was unavailable because the district court cut off cross-examination as to one such witness and because there was no way to know that the other witness told a witness who testified at resentencing that he was lying. Finally, we are unpersuaded that, in light of this, the district court abused its discretion in continuing to rely on "unattributed statements by prosecutors and law enforcement agents" in the "First PSR without attribution of sources or verification permitting a court to evaluate their reliability," id.; in no way does this place Hammoud's case within the exception to the mandate rule.

Finally, we are not convinced that a "blatant error" in our prior decision will result in a serious injustice. In short, the district court did not err in adhering to the mandate and limiting resentencing to consideration of a variance sentence.4

B.

Hammoud next contends that the district court abused its discretion by admitting the testimony of Matthew Levitt, the Government's trial expert, and Special Agent Yu for resentencing. Specifically, he argues that the district court erred in considering Levitt's trial testimony during resentencing because new evidence undermined the accuracy of his testimony, and that the "failure to disclose material information about [his] bias and lack of expertise even if inadvertent[] is a second independent ground for exclusion." Hammoud's Br. 62. He also argues that admitting the testimony with the restriction of cross-examination of Levitt, and Yu regarding Harake, consisting of hearsay, "without disclosing sources," violated the Confrontation Clause and due process.5 Id. at 62-63.

Having reviewed the briefs, the record and the applicable law, we reject Hammoud's arguments. See United States v. Brooks, 524 F.3d 549, 564 (4th Cir. 2008) (reviewing decision to admit evidence for sentencing purposes for an abuse of discretion). The district court was within its discretion to rely on Levitt's testimony; we do not believe the new evidence or Levitt's alleged bias or lack of expertise has so undermined his trial testimony as to make it unreliable on due process grounds or under the guidelines. Furthermore, admitting this testimony despite restricting cross-examination neither violated the Confrontation Clause, see United States v. Powell, 650 F.3d 388, 393-94 (4th Cir. 2011) (holding that the "Confrontation Clause does not apply at sentencing" and affirming district court's reliance on hearsay evidence found within presentence report to support imposition of enhanced sentence), nor due process, see id. at 394 (holding that hearsay evidence admitted without cross-examination can be reliable enough for use at sentencing). In sum, we are confident that the disputed evidence was reliable and that the district court did not abuse its discretion in considering it during resentencing.

C.

Finally, we consider and reject the parties' arguments challenging the reasonableness of the sentence. See United States v. Mendoza-Mendoza, 597 F.3d 212, 216 (4th Cir. 2010) ("[A]ppellate courts examine sentencing determinations under an abuse-of-discretion standard, which translates to review for `reasonableness.'").6

Hammoud raises three primary challenges to his sentence. He attacks the 30 year sentence as unreasonable because it is disproportionately high by comparison to any comparable § 2339B or terrorism cases, to the statutory penalty for material support and to the policies underlying U.S.S.G. §§ 2M5.3 and 3A1.4, and because it is constitutionally disproportionate. He also contends that consideration of the factors in § 3553(a)(1) through (a)(4) establishes that the 30 year sentence is an abuse of discretion, particularly because the nature and circumstances of the offense do not justify a 30 year sentence and the "alleged Hezbollah connection" is not a ground upon which to impose a 30 year sentence. Hammoud's Br. 57. Finally, Hammoud contends that the district court erred by finding that his criminal history category was VI under § 3A1.4, pointing to § 3553(a)(1).

The Government cross-appeals and argues that the district court abused its discretion "by granting a major downward variance without providing a legitimate and `sufficiently compelling' justification for doing so." Government's Br. 27. Specifically, the Government argues that the district court arbitrarily imposed a sentence without giving meaningful consideration to § 3553(a), that the district court erred in its application of § 3553(a)(6) by relying on a comparison of defendants not similarly situated, and that none of the "purported" variance justifications "are sufficiently compelling to overcome the court's misapplication of § 3553(a)(6)." Id. at 28.

We understand these challenges primarily to sound in substantive reasonableness because they attack the length of the sentence under the § 3553(a) factors rather than the methods used in reaching the sentence. In any event, the district court clearly did not procedurally err. The district court followed the sentencing methodology we have previously laid out. The district court used the guidelines calculation we affirmed as a starting point, gave the parties an opportunity to argue for what they believed was an appropriate sentence, carefully and thoughtfully considered the § 3553(a) factors, made an individualized assessment based on the facts, and adequately explained the sentence.

Having found no significant procedural error, we must consider the substantive reasonableness of the sentence, "examin[ing] the totality of the circumstances to see whether the sentencing court abused its discretion in concluding that the sentence it chose satisfied the standards set forth in § 3553(a)." Mendoza-Mendoza, 597 F.3d at 216. We "may consider the extent of the deviation" from the guidelines range but "must give due deference to the district court's decision that the § 3553(a) factors, on a whole, justify the extent of the variance." United States v. Diosdado-Star, 630 F.3d 359, 366 (4th Cir. 2011) (quoting Gall v. United States, 552 U.S. 38, 51 (2007)). "Although the district court's justification for the sentence must support the degree of the variance, and a major departure should be supported by a more significant justification than a minor one, . . . a district court need not justify a sentence outside the Guidelines range with a finding of extraordinary circumstances." Id. (internal quotation marks and brackets omitted) (quoting United States v. Evans, 526 F.3d 155, 161 (4th Cir. 2008)); see also Abu Ali, 528 F.3d at 261 ("As the Supreme Court observed in Gall, when determining whether the district court's proffered justification for imposing a non-guidelines sentence `is sufficiently compelling to support the degree of the variance,' common sense dictates that `a major departure should be supported by a more significant justification than a minor one.'").

Finding the parties' arguments lacking in merit, we affirm the district court's variance sentence of 30 years' imprisonment. While certainly substantial, the variance incorporated into the district court's sentence does not constitute an abuse of discretion. The district court carefully considered how the § 3553(a) factors applied to Hammoud (not merely reciting the statutory language) and adequately explained its decision, as evidenced by its nine-page sentencing memorandum. Considering the totality of the circumstances, the district court's several justifications provided in its analysis of § 3553(a) are sufficiently compelling to support the variance in this case.7

The district court carefully considered the § 3553(a) factors in justifying its variance sentence. Under § 3553(a)(1), the district court appropriately weighed in favor of Hammoud that he had "no prior criminal convictions," that "[t]he crimes of which he was convicted were not crimes of violence or conspiracies to commit violence" and that the "crimes had no identifiable victim." J.A. 5312. Indeed, the district court recognized its discretion to depart or vary downward if it believed § 3A1.4 "overrepresent[ed] the seriousness of [Hammoud's] past criminal conduct or the likelihood that [Hammoud] will commit other crimes," but the district court found that the terrorism enhancement and resulting criminal history level "will not change and should not be changed based on the evidence of his involvement with Hezbollah, his relative youth and thus time and ability to become a recidivist, and the fact that he never accepted responsibility and obstructed justice by testifying falsely at trial."8 J.A. 5312-13. In other words, the district court, thoroughly familiar with Hammoud's case, recognized its discretion but apparently (albeit implicitly) considered and credited the trial evidence over the sentencing evidence as it was entitled to do in reaching this conclusion.9

The district court also thoroughly considered other § 3553(a) factors: (1) "the need for the sentence imposed to reflect the seriousness of the offense and to provide just punishment," balancing "the seriousness of any terrorism offense" with "the lack of violence here," J.A. 5313-14; see 18 U.S.C. § 3553(a)(2)(A); (2) "the need for the sentence imposed to afford adequate deterrence to criminal conduct," balancing Hammoud's age, his potential risk of recidivism in light of his "almost certain[]" deportation upon release from prison, and "legislative intent" reflected in the terrorism enhancement, J.A. 5314; see 18 U.S.C. § 3553(a)(2)(B);10 (3) "the need for the sentence imposed to protect the public from further crimes of the defendant," considering that Hizballah is a DFTO and that Hammoud "had ties to the organization, even if his [individual, actual] activities were nonviolent," J.A. 5314; see 18 U.S.C. § 3553(a)(2)(C); (4) "the kinds of sentence and the range established for the applicable category of offense committed by the applicable category of the defendant," recognizing that the guidelines calculation is only "a starting point" to be considered in the variance analysis and that Hammoud had obstructed justice by testifying falsely at trial, J.A. 5315; see 18 U.S.C. § 3553(a)(4);11 (5) "pertinent policy statements" from the Sentencing Commission, i.e., Congress's "policy choice in giving a terrorism enhancement for a greater criminal history even when the specific defendant has no criminal history," J.A. 5316; see 18 U.S.C. § 3553(a)(5); and (6) the "need to provide restitution" to any victims, J.A. 5317; see 18 U.S.C. § 3553(a)(7). Neither party has demonstrated that the district court clearly erred in making its findings under each of these factors.

Though it raises the most concern for the parties here, we discern no error in the district court's consideration of § 3553(a)(6). Explicitly recognizing that the need to avoid unwarranted sentencing disparities among defendants with similar records should not be given "extraordinary weight," the district court considered this factor along with its consideration of the other factors. J.A. 5316; cf. Abu Ali, 528 F.3d at 262-67 (holding that the district court erred when its consideration of § 3553(a)(6) "served as the driving force behind its ultimate determination"); United States v. Khan, 461 F.3d 477, 500-01 (4th Cir. 2006) (holding that the district court erred when it placed "`excessive weight'" on § 3553(a)(6)). The district court appropriately considered cases "in which the defendant [likewise] went to trial" and "was convicted by a jury of a terrorism . . . offense, particularly under Section 2339," and then concluded that "in examining cases that fall within those parameters," Hammoud's [original] sentence "appear[ed] grossly disproportionate." J.A. 5316-17; cf. Abu Ali, 528 F.3d at 262-67 (holding that the district court erred when it compared Abu Ali to defendant who pled guilty and whose conduct underlying crimes of conviction was different in "substance and scope" and improperly compared Abu Ali with others, "overlook[ing]" "unrealized harm" and differences in the "serious[ness] and significan[ce of] steps" taken and in the "infliction of harm"); Khan, 461 F.3d at 500-01 (holding that the district court erred when it considered defendant who pled guilty similarly situated to defendant who went to trial). In its sentencing memorandum, the district court cited to nine cases with brief explanations of the defendants' convictions and sentences that it considered within these parameters. See J.A. 6499, 6501-02. The district court then concluded that, in the cases cited by the parties, no defendant "received a sentence in excess of 1800 months," "life imprisonment was ordered [in] cases of violence," and lighter sentences compared to Hammoud's [original] sentence were imposed in cases "in which violence or mass physical carnage was possible." J.A. 5316-17.

Consideration of a "vast summary of cases," J.A. 5317, allowed the district court to reach these few broad conclusions en route to imposing a sentence sufficient but not greater than necessary to comport with the purposes of sentencing. The district court, focused on individually assessing the facts of Hammoud's case, had no obligation to, as Hammoud argues, "explain why [his] sentence is 2.2 times greater than the average for all terrorism cases and four times the average for all financing cases." Hammoud's Br. 38. Rather, the district court appropriately used a certain subset of cases to conclude that a 155 year sentence was "grossly disproportionate" and "reviewed the vast majority of cases and applicable sentences" to reach certain other summary conclusions. J.A. 5317. In this way, the district court, considering § 3553(a)(6) among the other factors, balanced an individual assessment in the case before it with a broad review of cited cases to ensure that Hammoud's sentence would not result in "unwarranted sentence disparities among defendants with similar records who have been found guilty of similar conduct."12 18 U.S.C. § 3553(a)(6).

Given the justifications provided by the district court, we are loath to find fault with the result reached. We agree with the observation made by the First Circuit that there is "a range of reasonable sentences," and that an appellate court should only reverse if the "sentencing court's ultimate determination falls outside the expansive boundaries of that universe." United States v. Martin, 520 F.3d 87, 92 (1st Cir. 2008). The district court's determination has not so fallen here. In short, considering the totality of the circumstances, the district court, in a superior position, particularly given the history of this challenging case, explained the variance with sufficiently compelling justifications under the § 3553(a) factors.

III.

Having found no reversible error, we affirm the judgment of the district court.

AFFIRMED.