[Opinio Juris note: Geoffrey Corn, a former Opinio Juris guest blogger who is a military law expert teaching at South Texas Law School, has sent along the following thoughts on the Military Commission Act.]

It is by now apparent to most interested observers (and probably quite a few not so interested observers) that the Military Commission Act of 2006 has triggered a barrage of commentary and criticism. The initial focus on the amendments to the War Crimes Act has now shifted to expressions of dismay over the broad definition of “unlawful enemy combatant.”

In response to a request by the Asser Institute of International Humanitarian Law in the Netherlands, I provided some initial thoughts on the originally released “compromise” Bill (available here). In this commentary, I provided my assessment of the amendment to the War Crimes Act, to include my thoughts on how the amendment apparently transformed offenses in violation of common article 3 into specific intent crimes, which I consider a subtle but potentially profound modification. I then attempted to highlight what I considered the improvements to the Commission process resulting from analogy to the courts-martial system, and also what I considered unresolved deficiencies in that process.

One aspect of the MCA that I have been thinking of recently is the scope of the jurisdiction granted to the Military Commissions. According to the statute:

“A military commission under this chapter shall have jurisdiction to try any offense made punishable by this chapter or the law of war when committed by an alien unlawful enemy combatant before, on, or after September 11, 2001.”

This jurisdiction obviously expressly expands the jurisdiction of the Military Commission beyond offenses in violation of the laws of war. This is probably a response to the pre-Hamdan defense assertions that many of the prosecution allegations failed to allege violations of the laws of war applicable to their clients. It seems that Congress has answered this challenge by simply granting the Commission statutory jurisdiction over theses offenses. But I think this raises two very significant questions.

First, can Congress validly grant jurisdiction to the Military Commission for any non-law of war violation? Article 21 of the UCMJ certainly suggests that a Military Commission may exercise jurisdiction over offenses defined by either the laws of war or by statute when it says “The provisions of this chapter conferring jurisdiction upon courts- martial do not deprive military commissions, provost courts, or other military tribunals of concurrent jurisdiction with respect to offenders or offenses that by statute or by the law of war may be tried by military commissions . . .” However, it seems to me that this “by statute” clause of Article 21 must be narrowly construed to refer to non-law of war violations historically subject to such military jurisdiction. I am specifically referring to espionage and related wartime crimes associated with armed conflict that are not considered violations of the laws of war but nonetheless historically subject to prosecution by military courts.

This limited extension of military commission jurisdiction is actually reflected in the punitive articles of the UCMJ. Most of the offenses defined by the Code are not subject to trial by military commission, but only by courts-martial (which means only individuals subject to the Code at the time of violation may be charged with such offenses, a category that does not include pre-capture enemy personnel). The only two offenses that are expressly made subject to trial by military commission in addition to courts-martial are “spying” and “aiding the enemy”, both of which are historically subject to military jurisdiction even though they are not considered violations of the laws of war.

Article 18 of the UCMJ also bolsters this limited extension of military commission jurisdiction. Article 18 establishes the jurisdiction of the general courts-martial. This grant of jurisdiction includes two categories. First, only individuals subject to the UCMJ may be tried by general courts-martial for violating the prohibitions of the code established by the punitive articles. Second, any “person who by the law of war is subject to trial by a military tribunal” may be tried by general courts-martial. This seems to reflect the principle that although the jurisdiction of this military court does extend beyond individuals subjected the punitive articles of the UCMJ, the extension is limited to offenses in violation of the laws of war.

Congress does not seem to have perceived any limit to the range of non-law of war offenses that may be subjected to trial by military commission. Considering the military commissions are creatures of the laws and customs of war, or as some commentators have labeled them, “war courts”, I have a hard time reconciling this view of jurisdiction. I do not dispute that some offenses may be subjected to trial by military commission by statute, but I think this is a limited category of customarily accepted “battlefield” crimes that are not prohibited by the law of war for the simple reason that every nation authorizes them – like espionage. Crimes such as terrorism, hijacking, providing material support to terrorism, perjury, and conspiracy don’t seem to me to fall into this category. Nonetheless, they are now by statute subject to trial by the Military Commission. If these offenses are not derived from the laws of war, what special competence does a Military Commission have to adjudicate such crimes? In my mind, none, which leads me to conclude that granting the Commission jurisdiction over such offenses is just easier than trying them in an Article III court.

The other aspect of this expansion in jurisdiction that I find troubling is that it seems to violate the nulle crimen principle. Even if Congress can subject such offenses to trial by military commission, they were not subject to this jurisdiction before now. Nonetheless, the statute indicates that any person who violated these provisions “before, on, or after September 11, 2001” is subject to trial by Military Commission. Again, I have no problem with the government alleging an individual committed a violation of the laws of war and subjecting such an offender to the jurisdiction of a military commission. So long as the government alleges and proves the requisite jurisdictional predicate – that the law of war applied to the individual and proscribed the alleged misconduct at that time – there is no ex post application of law. However, this is far different from Congress defining a list of offenses not derived from the laws of war, and then establishing retroactive jurisdiction over these offenses by simply placing them under the umbrella of the jurisdiction of a “war court.”