The Executive Branch and International Law

This article challenges the view that the constitutional obligation of the President of the United States to “take care that the laws [are] faithfully executed” does not oblige him to conform American foreign policy to customary international law. In particular, it argues that rules of customary international law were not among the “laws” to which the constitutional language refers, that the federal courts’ authority to create federal common law does not extend to the types of questions addressed by customary international law, and that in any event decisions by the judiciary requiring the President to conform to customary international law would raise serious separation of powers problems.