The Constitution of the United States does not explicitly define the extent of the President’s authority to involve United States troops in conflicts with other nations in the absence of a declaration of war. Instead, the question of the President’s authority in this matter falls in the hazy area of concurrent power, where authority is not expressly allocated to either the President or the Congress. The Constitution gives Congress the basic power to declare war, as well as the authority to raise and support armies and a navy, enact regulations for the control of the military, and provide for the common defense. The President, on the other hand, in addition to being obligated to execute the laws of the land, including commitments negotiated by defense treaties, is named commander in chief of the armed forces and is empowered to appoint envoys and make treaties with the consent of the Senate. Although this allocation of powers does not expressly address the use of armed forces short of a declared war, the spirit of the Constitution at least requires that Congress should be involved in the decision to deploy troops, and in passing the War Powers Resolution of 1973, Congress has at last reclaimed a role in such decisions.
Historically, United States Presidents have not waited for the approval of Congress before involving United States troops in conflicts in which a state of war was not declared. One scholar has identified 199 military engagements that occurred without the consent of Congress, ranging from Jefferson’s conflict with the Barbary pirates to Nixon’s invasion of Cambodia during the Vietnam conflict, which President Nixon argued was justified because his role as commander in chief allowed him almost unlimited discretion over the deployment of troops. However, the Vietnam conflict, never a declared war, represented a turning point in Congress’s tolerance of presidential discretion in the deployment of troops in undeclared wars. Galvanized by the human and monetary cost of those hostilities and showing a new determination to fulfill its proper role, Congress enacted the War Powers Resolution of 1973, a statute designed to ensure that the collective judgment of both Congress and the President would be applied to the involvement of United States troops in foreign conflicts.
The resolution required the President, in the absence of a declaration of war, to consult with Congress “in every possible instance” before introducing forces and to report to Congress within 48 hours after the forces have actually been deployed. Most important, the resolution allows Congress to veto the involvement once it begins, and requires the President, in most cases, to end the involvement within 60 days unless Congress specifically authorizes the military operation to continue. In its final section, by declaring that the resolution is not intended to alter the constitutional authority of either Congress or the President, the resolution asserts that congressional involvement in decisions to use armed force is in accord with the intent and spirit of the Constitution.
It can be inferred from the passage that the War Powers Resolution of 1973 is applicable only in “the absence of a declaration of war” because