The text of the legislation spells it out plainly. This is the law.

Section 2(c) of the War Powers Resolution (50 U.S.C. § 1541) states:

“The constitutional powers of the President as Commander-in-Chief to introduce United States Armed Forces into hostilities, or into situations where imminent involvement in hostilities is clearly indicated by the circumstances, are exercised only pursuant to (1) a declaration of war, (2) specific statutory authorization, or (3) a national emergency created by attack upon the United States, its territories or possessions, or its armed forces.

By extension,

“This framework emphasizes the importance of congressional oversight and the need for a clear legal basis before the nation engages in military action. Such measures are designed to prevent unilateral decisions that could lead to prolonged conflicts without proper justification. Moreover, this delineation of power aims to uphold the principle of checks and balances within the government, ensuring that the grave decision to commit troops in combat is made with careful consideration and, when possible, consensus among elected officials.”