The Story of the Paquete Habana: Customary International Law as Part of Our Law

Abstract

The Paquete Habana is famous for its statement that international law is part of our law, for what it says about consulting the works of scholars and the evolving nature of international law, and for its suggestion that customary international law might be superseded as a rule of decision by a controlling executive act. As one chapter in the forthcoming book International Law Stories, this paper tells the story of The Paquete Habana. Most of the statements for which The Paquete Habana is famous simply repeat principles that date to the eighteenth century. But the underlying conception of international law had changed during the nineteenth century from a foundation in natural law to a positivism based on state practice and consent. While The Paquete Habana reflected that transition, it also stands for continuity and for accommodation of the original understanding of customary international law as part of the domestic legal system. The Paquete Habana's dictum about a controlling executive act, however, was new and inconsistent with the nineteenth century understanding of the roles of the President and Congress. This paper suggests that it resulted from Justice Gray's attempt to strengthen his opinion by demonstrating that the executive branch had not intended to violate customary international law in this case.