During the ratification debates on whether to accept the United States Constitution, Alexander Hamilton purported that there are both pretended and just causes of war. With this reality in mind, the framers of the Constitution sought to address the urgent need of the nation to defend itself, while simultaneously preventing the machinery of war from becoming a tool of oppression. To achieve this dual purpose, the Constitution, in Article I, Section 8, Clause 11, gives Congress the power to declare war. Having Congress declare war allows a waiting time before engaging in hostilities and demonstrates respect for American democratic traditions. The formal declaration of war by the legislature also legitimizes military action to the world. Additionally, by limiting Congress to declaring war, the Constitution leaves open the ability to make war, in instances such as sudden attack, to the president.

Time

Having Congress declare war provides an essential waiting period between an emotional event and the initiation of hostilities. There are two chambers of Congress -- the House of Representatives and the Senate -- both of which must meet separately to declare the nation at war. The time required to assemble Congress, especially if it is not currently in session, serves as a check to heat of the moment decisions. Article 2, Section 3, allows the president to convene Congress in emergencies, which would include a prospective military conflict. Nevertheless, the time required to travel to the Capitol limits the spontaneity of a request to convene.

Democratic

Congress is the branch of government most directly responsive to the immediate wishes of the people. Providing Congress with the power to declare war demonstrates respect for democracy. Of the three branches of government, Congress possesses a closer relationship to the people as representatives of localities and states. Apportionment of state delegations in the House of Representatives corresponds to the population of districts. Meanwhile, each state has two senators. There are congressional elections at least every two years, ensuring that the overall body tends to reflect the current desires of the citizenry as nearly as possible.

International Harmony

War is a destructive and costly affair. Other nations have a stake, even if not directly involved in the conflict, in the result of war. Therefore, an official declaration of war, following a procedure recognizable to the international community, legitimates American military actions. Having Congress declare war is thus a means of ensuring good relations with the global community.

Making War

Though some view the declaration of war power as a limitation on executive authority, in reality the president retains the ability to make war, especially in case of sudden attack. In earlier drafts of the Constitution, the framers actually used the words “make war” rather than “declare war,” for the authority it would give Congress. The decision to restrict Congress to declaring war left the President with the implied power to make war. As the commander-in-chief, the president has the responsibility for ensuring national security.