CONSERVATIVE LEGAL SCHOLARS HAVE LONG warned that judges' reliance on foreign opinions might undermine the mechanism for setting domestic policy under the Constitution. Now, for the second time, a friend of the court brief has been submitted to the Supreme Court by foreign politicians in a case relating to detainees at Guantánamo, suggesting that constitutional control over foreign policy could be similarly jeopardized.

The case is Hamdan v. Rumsfeld, challenging the administration's military commissions for trying Guantánamo detainees. In the course of the litigation, a shifting group of "current and former members of the United Kingdom and European Union Parliaments" has filed a series of amicus briefs urging the Court to strike down the commissions. Although the original brief had 271 signatories, the number had ballooned to 422 by the time the Supreme Court decided to hear the case.

The submission that these "friends" filed makes clear that they seek to end the military commissions on the basis of international opinion rather than U.S. law, though they couch this argument in legalese. The brief notes in the opening section that it won't address any of the contested issues of U.S. law because "to the outside world it boils down to the simple, but crucial, question of whether the system of legal norms that purports to restrain the conduct of states vis-à-vis individuals within their power will survive the terrorist threat."

Although the brief goes on to say that Hamdan is "one battle in the war between the evil logic of terrorism" and the principle that "all states are subject to the rule of law," the brief itself essentially ignores the rule of law. It cites no federal statutes. It cites only four Supreme Court cases--and these only to support tangential statements--but references a full 20 cases from tribunals outside the United States. These mainly come from international bodies (such as the U.N., the International Court of Justice, and even the International Criminal Tribunal for the former Yugoslavia) but also include a couple of U.K. cases.

Moreover, the brief relies on a number of documents of dubious domestic import. Three treaties are central to its argument, though none is applicable. Two were ratified by the Senate with the express reservation that they would be of no domestic effect until Congress passed legislation implementing them, which it has not done. And the third wasn't even ratified. The brief argues that, as a signatory, the United States is nonetheless obliged to implement its protections.

It should perhaps be unsurprising that foreign legislators are now submitting amicus briefs designed to pressure the judiciary. After all, it appears that the federal government's most vocal proponents of respect for the international community's views can be found not in the State Department, but on the Supreme Court. In a 2005 speech to the American Society of International Law, Justice Ginsburg quoted the Declaration of Independence (complete with gender-sensitive modifications) to assure the audience that "we will continue to accord 'a decent Respect to the Opinions of [Human]kind' as a matter of comity and in a spirit of humility." Justices Breyer and Kennedy and retired Justice O'Connor have made similar remarks.

Thus, while it isn't unusual for foreign nations to submit amicus briefs where the issue is an interpretation of international law, they now appear to be doing so in an entirely new class of cases, first in the 2004 Guantánamo-related Rasul v. Bush, and now in Hamdan. Although electronic databases lack comprehensive coverage of brief submissions, it appears that before Rasul, when court cases touched on foreign policy issues, foreign officials weighed in only to represent the interests of a sovereign nation (for example, in commerce or admiralty cases) rather than to advance the more amorphous concept of "international opinion." In Rasul, an amicus brief was submitted by 175 "members of both Houses of the Parliament of the United Kingdom of Great Britain and Northern Ireland." The Bush administration lost that case--and if it loses in Hamdan, this trend will likely accelerate.