Abstract: Presidents have come to dominate the making, interpretation, and termination of international law for the United States. Often without specific congressional concurrence, and sometimes even when it is likely that Congress would disagree, the President has developed the authority to: (a) make a vast array of international obligations for the United States, through both written agreements and the development of customary international law; (b) make increasingly consequential political commitments for the United States on practically any topic; (c) interpret these obligations and commitments; and (d) terminate or withdraw from these obligations and commitments. While others have examined pieces of this picture, no one has considered the picture as a whole. For this and other reasons, commentators have failed to appreciate the overall extent of presidential unilateralism in this area, as well as the extent to which presidents are able to shift between different pathways of authority in order to circumvent potential restraints. This trend, moreover, has become more pronounced in recent years. In many ways, the growth of this vast executive control over international law resembles the rise of presidential power in other modern contexts ranging from administrative law to covert action. Unlike in those other contexts, however, there is no systematic regulatory or judicial apparatus to guide or review the exercise of presidential discretion in this context. This is true even though international law often plays a significant role in the U.S. legal system and has direct and indirect effects on U.S. institutions and persons. After presenting a descriptive account of the rise of presidential control over international law, the Article turns to normative issues. It argues that, although much of this practice has a plausible legal foundation, some recent presidential actions relating to international agreements, and some supportive claims made by commentators, are questionable in light of generally accepted principles relating to the separation of powers. It also explains why presidential control over international law should become significantly more transparent, and it considers the costs and benefits of additional accountability reforms.