War Powers Act
The War Powers Act states that the President of the United States cannot carry out a war without Congress's approval. Congress must be informed before the President commits troops, and the President must have the approval of Congress before deploying troops longer than 60 days.
The War Powers Act is also referred to as the War Powers Resolution (Sec. 1).
Two separate but closely related issues confront Congress each time the President introduces armed forces into a situation abroad that conceivably could lead to their involvement in hostilities. One issue concerns the division of war powers between the President and Congress, whether the use of armed forces falls within the purview of the congressional power to declare war and the War Powers Resolution (WPR).
The other issue is whether or not Congress concurs in the wisdom of the action. The purpose of the War Powers Act is to ensure that Congress and the President share in making decisions that may get the United States involved in hostilities.
Compliance becomes an issue whenever the President introduces U.S. forces abroad in situations that might be construed as hostilities or imminent hostilities. Criteria for compliance include prior consultation with Congress, fulfillment of the reporting requirements, and congressional authorization.