UC Davis

One of the principal aims of the U.S. Constitution was to give the federal government authority to comply with its international legal commitments. The scope of Congress’s constitutional authority to implement treaties has recently received particular attention. In Bond v. United States, the Court avoided the constitutional questions by construing a statute to respect federalism, but these questions are unlikely to go away. This Article contributes to the ongoing debate by identifying the Offenses Clause as an additional source of Congress’s constitutional authority to implement certain treaty commitments. Past scholarship has assumed that the Article I power to “define and punish...Offences against the Law of Nations” is limited to customary international law. But the Framers of the Constitution understood the law of nations to include both custom and treaties, or what they called “the conventional law of nations.” The history and purpose of the Offenses Clause show that it was intended to reach treaties and — despite the prevailing view in the academy — that Congress and the Supreme Court have shared this understanding of the Clause through most of our nation’s history.