Customary International Law After Sosa

Another of the panels at the American Enterprise Institute conference last Tuesday dealt with customary international after Sosa v. Alvarez-Machain. The panel consisted of Julian Ku, David Moore, Beth Stephens, and myself, moderated by Jack Goldsmith.

Not surprisingly, the panelists had different views.Julian Ku advanced an argument that the President should exercise control over customary international law, in part because customary international law is based on state practice and because it is generally the executive who acts for the United States in establishing that practice. He suggested a rule of deference—perhaps even absolute deference—to the President’s interpretations of customary international law. One problem with this position, as Beth Stephens pointed out, is that it does not accord with what the Supreme Court actually did in Sosa. In the end, the Court agreed with the Bush Administration that brief arbitrary detentions do not violate any well-established norm of customary international law, but the Court engaged in its own analysis and showed no deference to the executive. There are at least two other objections. First, from an originalist point of view, the President had very little role to play in establishing the law of nations at the time of the Founding because that law rested on natural law rules deducible by courts rather than on state practice. Second, from a modern point of view, it is not only the practice of the United States that establishes customary international law, and unless the United States is a persistent objector during the creation of a new international law norm it will be bound by such a norm even if the President doesn’t like it.

David Moore, on the other hand, read Sosa as giving control over customary international law not to the executive but to Congress. Of course Congress has constitutional authority to “define and punish” offenses against the law of nations and is presumed also to be able to violate customary international law under the last-in-time rule. But Moore’s argument went beyond this, suggesting that the Sosa Court’s focus on congressional intent means that such intent should determine the extent to which customary international law is incorporated into the U.S. legal system more generally. Moore’s argument is original and provocative but in my view it misreads Sosa. First, it resurrects in somewhat different form the argument that the Supreme Court expressly rejected in Sosa—that Congress must expressly incorporate customary international law before courts may apply it. Second, it places too much reliance on the Sosa Court’s discussion of intent. In a case involving the interpretation of a statute, like the Alien Tort Statute, a focus on congressional intent is perfectly appropriate. That does not mean, however, that congressional intent has anything to say about the place of customary international law in the constitutional structure—its place under Article II’s take care clause, Article III’s grant of federal question jurisdiction, or Article VI’s supremacy clause, for example.

It was to those questions that I turned in my presentation, arguing that Sosa’s approach is to treat the incorporation of customary international law not in an all-or-nothing manner, but issue by issue, an interpretation I advanced in a previous article on Sosa. I argued that the original understanding was that the President is bound by customary international law under Article II, that cases arising under the law of nations are within the federal question grant of Article III, and (perhaps most controversially) that customary international law should bind the states under the supremacy clause.

Beth Stephens was the voice of reason and practicality. Among other things, she discussed Sosa’s impact on the corporate cases, arguing that the violations they allege are clearly actionable under Sosa. She also pointed out that the First Congress recognized both that private actors not acting under color of state law could violate some rules of the law of nations and that aiders and abettors of international law violations could be held liable. One such case, In re South African Apartheid Litigation, is currently pending before the Second Circuit and we will soon see if she is right.