The Executive’s Misplaced Reliance on War Powers "Custom."

The American Journal of International Law

This article is reproduced with permission from the July 2015 issue of the American Journal of International Law © 2015 American Society of International Law. All rights reserved.


Historical practice, or custom, has long been seen as a source of authority in the resolution of separation-of-powers disputes.1 In two recent cases assessing the limits to the president’s power regarding the recognition of foreign nations2 and the making of recess appointments,3 the Supreme Court heavily emphasized past practice. Historical practice, the Court said, reflects “the compromises and working arrangements that the elected branches of Government themselves have reached.”4 In the realm of war powers, the executive branch has long relied on custom to justify military initiatives that were carried out without congressional approval.5 In essence, the executive has argued that because force has been used in the past without congressional approval, the same is permissible in various other situations (for example, in the Dominican Republic, Grenada, Haiti, Kosovo, and Panama).6