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Much of the recent debate about the status of customary international law in the U.S. legal system has revolved around the alien tort provision of the Judiciary Act of 1789, currently section 1350 of Title 28. In Filártiga v. Peńa-Irala, the decision that launched modern human rights litigation in the United States, the Court of Appeals for the Second Circuit relied on the view that customary international law has the status of federal common law in upholding section 1350’s grant of federal jurisdiction over a suit between aliens. The court’s position that customary international law was federal law was the prevailing view at the time—a view that has subsequently been dubbed the “modern position.” It was the view set forth in the black letter of the Restatement (Third) of Foreign Relations Law. Filártiga triggered a revisionist challenge to the modern position, with revisionists arguing that customary international law has the status of federal law only if given that status through statute or treaty, or perhaps through sole executive action; in the absence of such incorporation, customary international law has, at best, the status of State law in our legal system.

Much of the ensuing scholarly debate about the status of customary international law has focused on human rights litigation under section 1350. The debate continues in the currently pending Kiobel v. Royal Dutch Petroleum Co., which, like Filártiga, concerns the applicability of section 1350 to litigation between two aliens based on human rights violations that occurred abroad.

The focus on section 1350—by critics and defenders of the modern position alike— has unfortunately diverted attention from the key concerns driving the modern position. The core tenets of the modern position are that customary international law is binding on the States, that federal interpretations of such law are binding on State courts, and that State court decisions regarding such law are reviewable in the federal courts. The modern position is based on an important structural insight well articulated by Hamilton in The Federalist: “[T]he peace of the WHOLE ought not to be left at the disposal of a PART.” The costs of a violation of international law by a state are borne by the nation, yet the benefits are enjoyed by the state alone. Though critics of the modern position have directed much of their fire at alien tort claims, these cases have never directly implicated the core of the argument for treating customary international law as federal law, and the fate of such claims does not depend on adopting or rejecting the modern position.

Publication Citation

106 Am. J. Int'l L. 531-546 (2012)