The current war powers debate often misses how Congress has repeatedly allowed the executive branch to improperly infringe upon its authority. Congress allowed President Truman to set a troubling precedent that subsequent presidents have used to continue to improperly expand their war powers.

The Framers rejected the British model that placed all powers over external affairs, including going to war, with the executive. They vested the war power in Congress, recognizing that the President could “repel sudden attacks.” In Federalist No. 4, John Jay warned about executive wars, stating that “nations in general will make war whenever they have a prospect of getting any thing by it; nay, absolute monarchs will often make war when their nations are to get nothing by it,” engaging in wars “not sanctified by justice or the voice and interests of his people.”

The United States followed that constitutional system from 1789 through World War II. Since that time, Presidents Truman, Clinton, and Obama have engaged in unconstitutional wars, deciding to seek authority not from Congress but instead from the U.N. Security Council or from NATO allies. It is sometimes argued that when presidents receive a resolution of support from the Security Council they satisfy international law. They do not, however, satisfy the U.S. Constitution. The Senate through the treaty process, such as agreeing to the U.N. Charter, may not transfer Article I powers of Congress to international or regional organizations. Presidential military initiatives after World War II have violated the rule of law, the principle of self-government, and the system of checks and balances.

In 1945, when Senators were debating the U.N. Charter, President Truman wired a note to Senator Kenneth McKellar (D-TN). He pledged that whenever the United States considered resolutions to use American troops in a U.N. military action, “it will be my purpose to ask the Congress for appropriate legislation to approve them.” Statutory authority would be needed from both houses of Congress. With that understanding, the Senate approved the U.N. Charter by a vote of 89 to 1.

It was then necessary for Congress to pass legislation to decide how the United States would agree to U.N. military actions. Under the Charter, all U.N. members would make available to the Security Council “on its call and in accordance with a special agreement or agreements,” armed forces and other assistance. Those agreements “shall be subject to ratification by the signatory states in accordance with their respective constitutional processes.” Congress had to decide how to articulate and honor those constitutional processes.

That congressional effort is expressed in the U.N. Participation Act, enacted in December 1945. The statute provides that agreements for the use of military force “shall be subject to the approval of the Congress by appropriate Act or joint resolution.” Advance congressional approval would be needed for involving U.S. forces in a U.N. military action. Truman signed this bill without expressing any constitutional or policy objections.

In 1950, by involving U.S. troops in a U.N. military action against North Korea, Truman violated the U.N. Participation Act, the U.S. Constitution, and his own personal pledge to Senator McKellar. At a news conference on June 29, a reporter asked him if the country was at war. He answered: “We are not at war.” Asked whether it would be more correct to call the operation “a police action” under the United Nations, he replied: “That is exactly what it amounts to.” As would be the case for subsequent Presidents, Truman decided to play games with words. At Senate hearings in June 1951, Secretary of State Dean Acheson conceded the obvious by admitting “in the usual sense of the word there is a war.” Federal and state courts regularly agreed that hostilities in Korea amounted to war.

Following Truman’s initiative, President Bill Clinton sought “authority” from the Security Council to use military force in Haiti and Bosnia. Unable to obtain U.N. authority to take military action in Kosovo, he reached out to NATO allies for support. At no time did he seek authority from Congress for those actions. His actions violated the Constitution.

On March 21, 2011, President Barack Obama reported to Congress that U.S. forces operating under a U.N. resolution had begun a series of strikes against Libyan air defense systems and military airfields “for the purposes of preparing a no-fly zone.” Those strikes, he said, “will be limited in their nature, duration, and scope.” The term “no-fly zone” might seem to some as so restrained that it would not reach the level of war. However, those military actions require destroying the capacity of a country to act against the United States and its allies. Regardless of how U.S. officials sought to downplay a no-fly zone, using military force against another country that has not threatened the United States is, as former Secretary of Defense Robert Gates said in his book “Duty,” published in 2015, an “act of war.” Very straight and important talk, respectful of constitutional values.

A memo released by the Office of Legal Counsel on April 1, 2011, chose to engage in various word games. It concluded that the military actions against Libya did not constitute “war” because of the limited “nature, scope, and duration” of the planned military operations. Although Obama anticipated that military actions would conclude “in a matter of days and not a matter of weeks,” they continued for seven months.



This piece is based on “Unconstitutional Wars from Truman Forward,” which appeared in the 2017 edition of Humanitas.