As Turkish forces swept into northern Syria after U.S. troops were pulled aside, enabling an assault on Kurdish forces and committing possible war crimes, many officials and commentators lamented the widely predicted escape of hundreds of detained Islamic State of Iraq and the Levant (ISIL) fighters who had previously been guarded by U.S.-backed Kurdish forces. Brushing off articulated fears that escaped ISIL fighters would pose a threat to the United States, however, President Trump predicted, with little apparent concerns for the United States’ closest allies, that “they’re going to be escaping to Europe.”

Yet before U.S. troops were withdrawn, they reportedly made plans to take custody of several dozen “high-value” ISIL detainees. As President Trump remarked last week, without offering details, “We are taking some of the most dangerous ISIS fighters out and we’re putting them in different locations where it’s secure.” In the chaos of an abrupt U.S. withdrawal, however, U.S. forces reportedly only succeeded in taking custody of two high-value ISIL detainees (and maybe some more lower-level fighters), whose fate now remains in question.

The two high-profile detainees recently transferred to U.S. custody were El Shafee Elsheikh and Alexanda Amon Kotey, half of the four-man cell allegedly responsible for notorious kidnapping and beheading of foreign hostages in Syria. Collectively known as “the Beatles” due to their British accents and nationalities, the four were allegedly responsible for the killing of American journalist James Foley, whose beheading along with harm to other foreign journalists, aid workers, and Syrian soldiers in 2014 was broadcast by the group in an online video.

Elsheikh and Kotey were captured in Syria last year by the Kurdish-led Syrian Democratic Forces (SDF) while engaged in battle against the ISIL. The other two members of the group include Mohammed Emwazi, who was reportedly killed in a drone strike in 2016, and Aine Davis, who has been convicted and imprisoned in Turkey on terrorism charges.

With Elsheikh and Kotey now in U.S. custody (presumably in the hands of the U.S. military), what is to become of them? Foley’s mother has called for her son’s killers to be prosecuted in the United States, noting the need for “some semblance of justice for the horrific execution and torture of the Americans.” The U.S. Department of Justice (DoJ) seems to agree, saying they want to bring the two men to trial in Virginia.

Under what authority can the U.S. detain and prosecute these men? There are several possibilities, each entailing various advantages and challenges. It is clear, however, that trial in our civilian criminal justice system is by far the best available solution given all we have learned in the post-9/11 era.

Prosecution by Military Commission

While the DoJ has already stated its plans to bring these two men to trial in the United States, it is worth considering the U.S. track record with fighters detained on various post-9/11 battlefields. At first, many of those captured in Afghanistan and elsewhere were brought to Guantánamo Bay, Cuba, and some were made subject to trial before military commissions there.

As is well known, the Bush administration’s initial military commissions were ruled unconstitutional in Hamdan v. Rumsfeld. The “reformed” commissions were convened for a handful of cases during the Obama and now Trump administrations. They are still struggling to get to the trial phase for the 9/11 case itself as of today, as explained here, here, and here. In short, this is an experiment in ad hoc justice that has failed miserably, to the detriment of the 9/11 victims, defence rights, and the rule of law. As such, a military commission is extremely unlikely to result in bringing the ISIL detainees to justice based on the track record to date.

 “Law of War” Detention

Separate from the issue of prosecution, there is also the option of continuing to hold the ISIL detainees in “law of war” detention, at least until the close of active hostilities with ISIL. Presidents Bush, Obama, and Trump have all maintained that their war-time detention authority derives from the President’s constitutional Article II authority and the 2001 Authorization for Use of Military Force (AUMF), which was passed by Congress in the wake of 9/11. The latter provides:

That the President is authorized to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons, in order to prevent any future acts of international terrorism against the United States by such nations, organizations or persons.

While the 2001 AUMF makes no mention of detention, the Supreme Court ratified this interpretation in Hamdi, declining to reach the Article II question “because we agree with the Government’s alternative position, that Congress has in fact authorized Hamdi’s detention, through the AUMF” (Justice O’Connor, writing for a plurality). Following Hamdi (and the 2008 Boumediene case), lower courts have accepted this argument in myriad habeas cases brought by Al Qaeda and Taliban fighters, and even some of their so-called “associated forces,” held at Guantánamo. (And the U.S. government has cited ongoing reliance on this detention authority as an argument against repealing the 2001 AUMF).

Use of the 2001 AUMF as applied to the U.S. military campaign against ISIL in Syria, however, remains controversial. While ISIL and al-Qaeda share common origins and brutal tactics, they are now fighting each other and exhibit substantial ideological and strategic distinctions. In addition, ISIL was not in existence at the time of the 9/11 attacks and so had no role in “planning, authorizing, committing, or aiding” those terrorist attacks. In any case, given persistent questions about how far the 2001 AUMF can be stretched, the U.S. has gone to considerable lengths to avoid a habeas case that would get to the merits on whether the AUMF covers ISIL (as discussed on these pages, here, and elsewhere).

Even assuming the AUMF provides detention authority for ISIL detainees, the question remains where the “Beatles” could be securely and humanely held. The United States has sometimes pursued law-of-war detention in theater, which also has the effect of limiting the ability of detainees to bring habeas challenges. For example, in Afghanistan during the Obama administration, most terrorist suspects and irregular combatants remained in military custody at the Bagram detention facility and were turned over to Afghan custody (some for prosecution there), repatriated, or resettled to third countries where necessary.

As compared to Afghanistan, the situation is far more complicated in Syria, of course, where the U.S. presence has always been minimal, is shrinking, and was already on shaky legal ground. Simply put, the prospect of creating a U.S. detention facility within Syria is far from a reliable solution on both practical and legal grounds, especially as the U.S. withdraws its forces and deserts its Kurdish allies.

This brings us to “law of war” detention outside of the theater in which the detainees were captured. Despite widespread criticism and multiple attempts to close the U.S. detention facility there, Guantánamo Bay remains open, and some U.S. officials continue to advocate for its use. Indeed, when “the Beatles” were first captured by Kurdish forces in early 2018, then-Attorney General Jeff Sessions, along with other key U.S. officials, remained in favor of initiating new proceedings before military commissions at Guantánamo Bay.

But as explained here and here, sending ISIL detainees to Guantánamo is a bad idea for strategic and legal reasons: (1) as explained above, it is unlikely to yield convictions in a military commission; (2) Congress has made trips to Guantánamo essentially a one-way proposition, making it unlikely that justice could ever be achieved in civilian courts within the United States if the Beatles spend any time there; and (3) as also noted above, bringing ISIL detainees to Guantánamo under law-of-war detention authority (whether for trial by military commission or not) opens the specter of a new habeas challenge that could invalidate the AUMF as the domestic legal basis for the entire U.S. fight against ISIL.

It is worth noting that in 2018, the U.K. Justice Secretary also drew fire for declining to comment on whether his country would oppose a potential transfer of the Beatles – its subjects – to Guantánamo. Commentators also criticized the U.K. for failing to pursue charges directly and for ultimately revoking the two men’s citizenship a few months later. On that, the question of whether states can render their own citizens/subjects stateless remains under-theorized in human rights law, even as the measure is becoming increasingly popular among states as a way to deal with their nationals who have joined terrorist groups. It is difficult to square this policy with the International Covenant on Civil & Political Rights, which at Article 24 sets forth the right to a nationality and at Article 12 the prohibition on being “arbitrarily deprived of the right to enter [one’s] own country.”

Civilian Courts in the United States

In light of the significant challenges described above, it would make the most sense for the U.S. to transfer Elsheikh and Emwazi to civilian custody as soon as feasible. Indeed, this has been done successfully in a few other cases. Many high-profile terrorist suspects have been tried and convicted in the United States in ordinary federal courts – including Richard Reid (the “shoe bomber”), Ramzi Yousef (1993 World Trade Center bomber), Faisal Shahzad (Times Square bomber), and Sulaiman Abu Ghaith (Osama bin Laden’s son-in-law), who pled guilty to conspiring to kill U.S. citizens – as explained here.

The DoJ has several options here, as we have briefly discussed previously.

First, it could take what is perhaps the easy way out: charge the men with providing “material support” for terrorism. The evidentiary bar here is quite low. The crime covers mere membership in a designated terrorist organization (with “material support” encompassing the provision of “personnel,” including oneself) or the provision of any number of forms of assistance to terrorists. Under §2339A, these charges can be initiated even before the individual is present within the United States. This statute applies to the provision of material support to a whole range of international offenses, including our suite of terrorism statutes and the killing of U.S. persons abroad. Under §2339B, by contrast, the offender – if not a U.S. citizen – must be “brought into or found” within the United States. This statute applies to individuals who assist terrorist organizations, including those designated as such by the State Department.

Second, the men could be charged with the killing or mistreatment of James Foley and other U.S. citizens under the War Crimes Act of 1996, as amended (18 U.S.C. § 2441). The War Crimes Act makes it a criminal offense to commit certain violations of the laws of war – including “grave breaches” of the Geneva Conventions (which apply to international conflicts) and of common Article 3 (which applies to non-international conflicts) – against a U.S. national or member of the U.S. Armed Forces, “whether inside or outside the United States.” It further defines such grave breaches to include a number of acts potentially applicable to the Foley case, including torture, cruel or inhuman treatment, murder, mutilation or maiming, intentionally causing serious bodily injury, and taking hostages (in addition to performing biological experiments, rape, and sexual assault or abuse).

While the U.S. has never prosecuted a person under the War Crimes Act, the Beatles offer the DoJ a unique opportunity to activate this statute, which implements the United States’ obligations under the 1949 Geneva Conventions. It would certainly send a strong signal for war crimes accountability.

These two sets of charges – for material support and war crimes – could be combined into a single indictment. One factor that makes this sort of comprehensive approach more difficult, however, is the fact that the DoJ has bifurcated its expertise in counterterrorism and human rights crimes into separate functional units. These units would need to coordinate among themselves on the theory of the case and then also work with the local U.S. attorney(s) with the ultimate authority to bring charges to encourage them to take a risk with inaugural war crimes charges.

Were a U.S. war crimes prosecution to get off the ground, several tricky issues remain. One is the question of whether the U.S. could muster enough admissible evidence of the two men’s involvement in the deaths of Foley or others. While there is indeed extensive evidence of the men’s involvement in ISIL’s operations, much of it may not be admissible in criminal proceedings (e.g., if it involves intelligence that cannot be declassified).

The Imperative of Assurances

Another question pertains to the use of the death penalty in the U.S. In Soering v. U.K., the European Court of Human Rights concluded that the extradition of a person facing a death sentence in the U.S. would violate the Article 3 of the European Convention on Human Rights (ECHR) (the treaty’s prohibition on “torture or to inhuman or degrading treatment or punishment.”). This has proven a challenge in the extradition of terrorism suspects from Europe. States have responded with the concept of assurances whereby the state that retains the death penalty promises not to employ it in the prosescution of the suspect. However, and controversially, British officials have already indicated their willingness to have the U.S. prosecute Elsheikh and Emwazi, even without seeking assurances that U.S. prosecutors would not seek the death penalty.

Arguably, the U.K. could seek such assurances now, even if retroactively and even when the Beatles are already in our custody. This very issue has gone up the U.K. courts on a petition by the mother of one of the men (before the two were in U.S. custody). The lower court did not object to the lack of assurances; the issue has now gone before the Supreme Court, which hasn’t yet ruled. In another case, the U.K. aggressively sought assurances from Pakistan that a Pakistani murder suspect would not be subject to the death penalty based on evidence turned over to Pakistan by the U.K. So, clearly, the Beatles present a special case in which former British subjects are receiving lesser protections than non-nationals accused of violent crimes.

To be sure, the U.K. has divested these men of their citizenship and does not have custody of them. However, as in the case involving Pakistan described above, the U.K. has in the past sought assurances even for non-nationals before sharing evidence in a case in which the accused could be put to death. Here, where the U.K. has forsaken its own subjects, it is imperative that U.K. authorities retain the practice and expectation of such assurances when potential capital charges in the United States are at issue, no matter how horrific the charges are against them.

Male Captus

Finally, there is some possibility that there have been enough irregularities around the circumstances of the Beatles’ capture or detention that it might divest a court of jurisdiction or lead to the exclusion of key evidence under some sort of male captus-male detentus or shock the conscience theory. This is speculative, of course, given the lack of details about the circumstances of the Beatles’ detention, treatment, and transfer.

Foreign or International Prosecution

Finally, of course, the United States could choose to yet again transfer Elsheikh and Emwazi to a foreign jurisdiction – such as the U.K. assuming its material support legislation applies – for prosecution. Although the International Criminal Court (ICC) has presumptive jurisdiction over the two men (given that the United Kingdom has ratified the Rome Treaty), so far no investigation into events in Syria has been triggered before the Court. To the extent that the Office of the Prosecutor is examining the situation in Iraq, it has focused exclusively on custodial abuses committed by British soldiers in Iraq from 2003-2008.

Concluding Thoughts

In sum, civilian prosecution in U.S. courts remains by far the best option for reliably bringing the two ISIL detainees in U.S. custody to justice. While the question of what charges to pursue is significant, it should not detract from the fact that only our civilian courts have proven up to the task of handling complicated, high-profile terrorism-related cases in the post-9/11 era. If justice is the goal, civilian courts are the answer. That said, the DoJ should look closely at whether this is the case to awaken the United States’ still dormant war crimes statute.

IMAGE: A Kurdish security officer, right, escorts Alexanda Amon Kotey, left, and El Shafee Elsheikh, center, allegedly among four British jihadis who made up a brutal Islamic State cell dubbed “The Beatles,” at a security center in Kobani, Syria, Friday, March 30, 2018. “The Beatles” terror cell is believed to have captured, tortured and killed hostages including American, British and Japanese journalists and aid workers. (AP Photo/Hussein Malla)