INTRODUCTION In this Article, I consider some of the constitutional implications of U.S. delegations of authority to international institutions. (1) Since World War II, there has been a vast growth in the number and importance of international institutions. Although some of these institutions are merely forums for discussion and negotiation, many of them exercise judicial, legislative, regulatory, investigative, or prosecutorial authority. Despite its isolationist reputation, and despite recently announcing that it would not become a party to the International Criminal Court, the United States has committed itself to many of these international institutions. By virtue of these commitments, the United States has consented to have international institutions make certain decisions, and take certain actions, that can affect the United States's rights and duties under international law and, in some instances, the enforceability of U.S. domestic law. Although the number and extent of future U.S. commitments will likely vary depending on the presidential administration, the general trend internationally--as illustrated most dramatically by developments in Europe--is towards vesting ever-increasing authority in international institutions.