Customary International Law: Its Nature, Sources and Status as Law of the United States

Abstract

This classic article addresses the nature, sources and status of customary international law as part of the constitutionally-based laws of the United States. In particular, there is detailed attention to two primary elements of customary international law: (1) general patterns of practice or behavior, and (2) general patterns of legal expectation or opinio juris. Additionally, there is detailed documentation of evidences of customary international law used by the U.S. judiciary. Attention is also paid to relevant views of the Framers and to early cases.

Keywords: bound, CIL, Congress, Constitution, customary, dynamic, evidence, expectations, Framers, General Assembly, generally shared, international law, judicial power, laws of the United States, opinio juris, part of our law, participant, practice, President, proof, source