The Hamdan case is back and yet again it offers an opportunity to explore a crucial aspect of the law of war.
Salim Hamdan was one of the first individuals charged before the U.S. Military Commissions. His challenge to the commissions’ jurisdiction went all the way to the U.S. Supreme Court, which concluded that the commission did not have jurisdiction over his case because, inter alia, the commission violated Common Article 3 of the Geneva Conventions. A four-justice plurality concluded that the inchoate offense of conspiracy was not a violation of the international laws of war that the Bush Administration was entitled to prosecute before a military commission.
After Congress passed the MCA of 2006 in response to the Hamdan decision, Hamdan was tried before a military commission for conspiracy and providing material support to terrorism. Ironically, the military jury acquitted him of conspiracy and only found him guilty of material support. He was sentenced to 5.5 years, transferred to Yemen, and subsequently released due to time served.
Although his sentence has long since been completed, his appeal of his conviction for material support is ongoing. The D.C. Circuit is now hearing the case, which is of immense importance between material support for terrorism is a key charge in both civilian and military commission cases against alleged terrorists.
The U.S. government has filed its brief in the case, and the document contains an interesting choice of language. (Analysis by Steve Vladeck here). In the past, the U.S. government has argued that material support for terrorism is a violation of the international law of war, and therefore punishable by military commission. However, the latest document exclusively uses an alternate formulation: material support for terrorism violates the U.S. common law of war, which the brief defines rather cryptically as "U.S. common law traditionally applied in wartime." The question is what that phrase really means and why it was used in this case.
The phrase “common law of war” is rather uncontroversial, and harks back to Ex Parte Quirin. Here’s how the Supreme Court defined it there:
The law of war, like civil law, has a great lex non scripta, its own common law. This “common law of war” (Ex parte Vallandigham, 1 Wall. 243, 249) is a centuries-old body of largely unwritten rules and principles of international law which governs the behavior of both soldiers and civilians during time of war. Winthrop, Military Law and Precedents (1920), 17, 41, 42, 773 ff.
However, Quirin never uses the phrase U.S. common law of war, and this new term of art appears to be made up. I know of no previous U.S. federal or state case that uses this exact term. If it appears anywhere else, I would appreciate knowing its provenance.
The shift from “international” to “U.S.” common law of war, if we are to put a coherent gloss on it, must mean something like this: what U.S. courts have interpreted the international law of war to be, in particular in the form of past practice before previous military commissions. In that sense, although U.S. common law of war does not represent international law per se, it does represent a kind of precedent that might have stare decisis value. Or more aptly, the U.S. common law of war, in the form of past practice, represents a gloss on international law that Congress was certainly entitled to rely on when it passed the Military Commissions Act, pursuant to its "Define and Punish Clause" power, and codified material support as a crime.
In other words, Congress’ decision, if consistent with the U.S. common law of war, was presumably reasonable and therefore should not be disturbed by the judiciary, absent unambiguous evidence that Congress clearly erred when it exercised its "Define and Punish" function. But what if the past practice was wrong? Or what if past practice was based on previous international law which has, in the interim, significantly evolved or changed? Can we continue to prosecute before a military commission a violation of the law of war that the international law of war no longer recognizes as a crime? This seems like an odd -- or at least uncomfortable -- result.
That’s my best guess on the significance of the phraseology. If anyone has a better idea, I would love to hear it. Either way, I would not be surprised if the Hamdan case goes back to the Supreme Court again.