Presidential constructive and deconstructive powers in foreign affairs: a study on unilateral withdrawal from international agreements in the Americas

This article explores the regulation of foreign affairs powers under international and constitutional law, with a focus on withdrawal from international agreements in presidential systems in the American continent. It seeks to demonstrate the existence of an imbalance between constructive and deconstructive powers in foreign affairs and to point out domestic and international effects arising from such imbalance. This exploration leads to the identification of different constitutional approaches to presidential foreign affairs powers in the American continent, with attention to the outcomes and challenges identified in each model. As most American countries do not establish clear constitutional provisions for parliamentary participation in the withdrawal and termination of international agreements, this study takes the U.S. and Brazil as case studies on how supreme courts have dealt with the issue. Finally, this article explores the constitutional consequences of the imbalance upon domestic separation of powers and the stability of the international order.