West Law Report

Sosa v. Alvarez Machain

Harvard Law Review leading case summary: Sosa v. Alvarez Machain (2004): (.pdf) (11 pages)

Controversy has surrounded the Alien Tort Statute (ATS) since the Second Circuit pulled it from centuries of obscurity in the landmark case of Filartiga v. Pena-Irala. The current debate within the judiciary and the acad-emy arises largely from the confluence of two great legal shifts during the twentieth century: the changed relationship between the federal courts and the common law since Erie Railroad Co. v. Tompkins, and the evolution of customary international law, particularly its increased attention to the rights and duties of individuals rather than of states.

Last Term, in Sosa v. Alvarez-Machain (2004), the Supreme Court entered the debate and held that the prohibition in customary international law against arbitrary detention was not defined specifically enough to allow a claim under the ATS. While the Court did decide that claims under recently developed norms of international law may indeed be ac-tionable under the ATS, Sosa failed to articulate a clear conception of the interaction between customary international law and domestic law, and offers little guidance to lower courts both within ATS doctrine and beyond.