War Powers in a Republic
The Framers gave close thought on where to locate the war power. They knew that British precedents, on which they relied extensively in so many areas, assigned all of external affairs--including the war power--to the king. Yet the Framers did not trust executive judgments in matters of war. They were in the process of creating a republican government, and understood from their study of history that executives, in their search for fame and glory, had a dangerous appetite for war. John Jay in Federalist no. 4 warned that monarchs in other nations "will often make war when their nations are to get nothing by it, but for purposes and objects merely personal, such as a thirst for military glory, revenge for personal affronts, ambition, or private compacts to aggrandize or support their particular families or partisans." Such motives prompted executives to engage in wars "not sanctified by justice or the voice and interests of his people" (Wright 1961, 101).
From 1789 to 1950, all of the major U.S. wars were either declared or authorized by Congress (Fisher 2004, 17-79). Over that period, presidents used military force a number of times without first obtaining congressional authority. None of those actions, however, could be called a major war. Edward S. Corwin said that the list of these presidential initiatives consisted largely of "fights with pirates, landings of small naval contingents on barbarous or semi-barbarous coasts, the dispatch of small bodies of troops to chase bandits or cattle rustlers across the Mexican border, and the like" (Corwin 1951, 16). A number of military initiatives were ordered not by the president but by naval officers and other military commanders, and some of those actions were later repudiated by the president (Wormuth and Firmage 1989, 149-51).
The Korean War
Respect for constitutional government ended abruptly in 1950 when President Harry Truman took the country to war against North Korea single-handedly. The academic community had an opportunity to challenge the legality of his actions, but chose instead to back what was deemed to be a politically defensible struggle against worldwide communism. Yet there was no need to make a choice between fighting communism and upholding the Constitution. Both could be achieved. If Truman decided he had to act first in an emergency, without congressional authority, he could have returned to Congress and sought statutory support. He chose not to.
On June 26, 1950, President Truman announced to the American public that the UN Security Council had ordered North Korea to withdraw its forces from South Korea and return to a position north of the 38th parallel. When North Korea failed to comply, Truman ordered U.S. air and sea forces to give support to South Korea. He made a commitment that the United States "will continue to uphold the rule of law" (Public Papers of the Presidents 1950, 492). In fact, Truman violated the U.S. Constitution, a congressional statute, the UN Charter, and his own public promises.
Consider the legislative history of the UN Charter. In 1945, senators debated language that called for member states to enter into "special agreements" when sending armed forces to the United Nations for collective military action. In an effort to build Senate support for the charter, Truman wired this note from Potsdam: "When any such agreement or agreements are negotiated it will be my purpose to ask the Congress for appropriate legislation to approve them" (U.S. Congress 1945). In this express manner, Truman publicly pledged to first seek statutory authority rather than assert a right to act unilaterally.
As ratified by the Senate, Article 41 of the UN Charter provides that all member states shall make available to the Security Council, in accordance with these special agreements, armed forces and other assistance. Each nation would have to ratify those agreements "in accordance with their respective constitutional processes. …