Editor’s Note: This is the most recent post in a mini-symposium leading up to next week’s en banc oral argument in the DC Circuit in Al Bahlul v. United States. You can check out all of the pieces in the series here.

For the second time, Al Bahlul v. United States is before the full DC Circuit. Previously, in July 2014, the DC Circuit sitting en banc upheld Ali Hamzi al Bahlul’s conviction for inchoate conspiracy by a military commission against an Ex Post Facto Clause challenge, although under a plain error standard of review (Al Bahlul II). This time, the Court will review the panel’s July 2015 ruling invaliding the conviction as a violation of Article III (Al Bahlul III). The en banc court’s July 2014 ruling in Al Bahlul II had remanded the case back to the original panel to consider al Bahlul’s other constitutional challenges. A divided DC Circuit panel then held in Al Bahlul III that Article III limited military commission jurisdiction to established violations of the international law of war, which inchoate conspiracy concededly is not, and rejected the US government’s theory that commission jurisdiction also encompassed violations of offenses traditionally triable in military commissions as part of a domestic common law of war.

The implications of the Al Bahlul litigation can be viewed in three main ways: (i) a one-off ruling that controls only al Bahlul’s case; (ii) a ruling that affects only “legacy” cases — i.e., prosecutions of remaining Guantánamo detainees whose conduct predates the 2006 Military Commissions Act (2006 MCA), the statute that codified conspiracy as an offense triable by military commission; and (iii) a ruling that affects prosecutions of all current and future detainees because it concerns the constitutional limits of military commission jurisdiction.

Al Bahlul II, which involved an Ex Post Facto Clause challenge to pre-2006 MCA conduct, concerned a combination of the first two possibilities. The holding, however, ultimately affected only al Bahlul because it rested on the plain error standard of review the court adopted due to al Bahlul’s failure to preserve his ex post facto challenge at trial. Al Bahlul III could similarly wind up as a one-off ruling because the government now maintains that al Bahlul’s constitutional challenge should be reviewed for plain error, in which case the precedent would be confined to al Bahlul’s case. But as the Al Bahlul III panel made clear, the government’s argument of waiver should fail because al Bahlul’s challenge presents a structural violation of Article III. Assuming that the en banc Court decides the current challenge under the ordinary standards of appellate review, as the panel did, Al Bahlul III will fall within the third category. That is, it will affect all present and future military commission prosecutions in which conspiracy and, potentially, other non-international law-of-war violations, such as material support for terrorism, are alleged as a basis of liability. (Al Bahlul II rejected material support as a basis for liability only for pre-2006 MCA conduct based on ex post facto grounds.)

This means that Al Bahlul III could have significant ramifications for the allocation of jurisdiction between Article III courts and military commissions for the prosecution of inchoate terrorism-related offenses going forward. (A ruling on the merits of al Bahlul’s challenge also means, as Steve observes, that the Supreme Court will be more likely to weigh in on the legality of military commissions again a decade after Hamdan v. Rumsfeld.) As the panel concluded, al Bahlul should win ultimately because the Supreme Court in Ex parte Quirin limited law-of-war commissions — those not created in occupied territory or during martial law — to trying violations of international law. (For various perspectives on the permissible limits of military commission jurisdiction, see articles by Steve Vladeck, David Glazier, and Peter Margulies). Quirin, moreover, was itself careful not to green-light any further military jurisdiction than necessary to allow for the military convictions in that case, one that involved a politically explosive situation of eight German saboteurs landing in the United States at the height of World War II and the express statements by President Roosevelt that the men be executed (six of the eight saboteurs eventually were).

In his post in this symposium, Peter Margulies points to the Quirin Court’s statement that it had “no occasion to define … with meticulous care the ultimate boundaries of military tribunals to try persons according to the law of war.” I view the Court’s language as indicating a concern about going any further than necessary rather than a suggestion that it could go further than it did. In any event, the Quirin Court’s reference point was international law.

In her dissent from the panel decision in Bahlul III, Judge Henderson suggests that the US could (again) be a leader in international law, as it was at Nuremberg, by forging a new path of international criminal liability for terrorism through an expanded conception of war crimes. She further intimates that failing to do so will leave the US vulnerable in the face of rapidly evolving terrorist threats. Neither strikes me as persuasive.

First, as I explain in greater detail in my Cambridge Journal of International & Comparative Law article, the US domestic law-of-war theory of liability is contrary not only to the letter of international criminal law, but also to its spirit. The main impetus behind the creation of modern international criminal tribunals is to fill a gap created by the failure, refusal, or inability of domestic courts to prosecute grave crimes. Indeed, under the complementarity principle codified in the Rome Statute, the International Criminal Court (ICC) will prosecute crimes only when domestic courts are unwilling or unable to do so. Since 9/11, the US has defended military commissions to prosecute offenses that it terms war crimes, such as conspiracy and material support, that Article III courts routinely prosecute as domestic offenses — and, moreover, prosecute with far greater efficacy than military commissions, which have been mired in uncertainty and delay. Creating a permanent alternative tribunal to facilitate convictions — a key purpose of military commissions as I explain in this Wisconsin Law Review article — will reinforce the United States’ place as an outlier, rather than a leader, in international criminal justice.

Second, the notion that the US will be left defenseless overstates the impact of this case and the asserted limits on commissions generally. Upholding the Al Bahlul III panel’s ruling would affect only the government’s power to try offenses that are not recognized as violations of international law in military commissions. The US could still prosecute actual law-of-war violations in commissions — such as deliberate targeting of civilians — which is alleged in the pending commission case against the 9/11 coconspirators. And it could still prosecute conspiracy and material support in Article III courts, as it has been doing. It could continue to detain individuals under law-of-war principles pursuant to the 2001 Authorization for Use of Military Force (AUMF), as the Supreme Court pointed out in Hamdan And it could continue to engage in targeted strikes pursuant to current legal authorities and policy guidelines. US detention and targeting practices remain controversial in their own right, but the limits on commission jurisdiction at issue in Al Bahlul IV will not affect them.

To date, the US has thus far pursued military commission charges against only one detainee that could implicate post-2006 MCA conduct (for more, see Steve’s post on the al-Iraqi case). So, one might reasonably wonder, what difference it makes on the ground if the government can prosecute conspiracy or other non-international law violations in military commissions, at least beyond the Guantánamo “legacy” cases.

While the current administration may not use commissions to bring any new cases on the basis of these controversial charges, it is uncertain what a future administration would do given the option. Guantánamo is likely to remain open and the war against al-Qaeda, ISIS, and other terrorist groups that can be squeezed within the AUMF’s ambit (or who are targeted by any new congressional force authorization) is certain to continue. Inchoate crimes, moreover, will undoubtedly remain the key tool in any counterterrorism prosecutor’s arsenal. The temptation to use commissions, therefore, will remain. And without any checks on the executive branch’s power to bring cases within this forum rather than Article III courts where that option exists, the specter of a militarized criminal justice system will continue as well.