An article by David Savage in the L.A. Times portrays Justice Kennedy's opinion in Boumediene as of a piece with his penchant for looking to foreign and comparative law for guidance in constitutional issues. The article---which accurately quotes me as agreeing with the basic thesis---notes that the opinion rests mostly on U.S. sources. The foreign cases cited are English cases, which are obviously relevant in assessing the historical scope of a legal form (habeas corpus) that the colonies and later the U.S. inherited from England. Nonetheless, Savage argues, and I agree, that Justice Kennedy's frequent exchanges with jurists on the world stage was likely influential.
I say in the story that the Kennedy opinion is "entirely in line with post-World War II human rights law . . . . One principle is you don't detain people without a trial." Now, this is indeed a principle of international human rights law (i.e., I agree with myself). See, for example, Article 9.4 of the International Covenant on Civil and Political Rights (ICCPR). It states: "Anyone who is deprived of his liberty by arrest or detention shall be entitled to take proceedings before a court, in order that that court may decide without delay on the lawfulness of his detention and order his release if the detention is not lawful." Yet merely to read this provision is to see a deep resonance with habeas corpus, and that's no accident: The ICCPR and, indeed, the foundational texts of modern international human rights laws, are in substantial measure, American products.
To be clear, the U.S. has taken the position, supported by the text of the ICCPR's Article 2, that the Covenant itself does not apply outside a country's territory. But of course Boumediene did not purport to apply the ICCPR. It applied the Suspension Clause of the Constitution, which has no clear territorial limit, at least not in the text.
My deeper point is that people who criticize Justice Kennedy and others for importing foreign notions into the Constitution when they rely on foreign and international materials are way off base. As the legal hegemon of the last 60 years, the U.S. has had a much greater impact on the global legal order than vice-versa, and that can only be to the benefit of the U.S. However, if the legal isolationists succeed in cutting off U.S. judicial participation in the global dialogue, then foreign and international law will stop looking to the U.S. as well. To use a trade analogy, it's foolhardy for a net exporter to ban imports, as that will only lead to retaliatory measures that hurt the exporter where it counts the most.
Posted by Mike Dorf