“Troops could not be expected … to march up to a surveyor’s line and stop,” remarked Secretary of State Dean Acheson, reflecting support for transforming the military objective from containment to elimination of the enemy and unification of Korea. Thus, for the only time during the Cold War, the United States tried to roll back communism by force. With UN approval, on September 27, 1950, Truman authorized MacArthur to cross the thirty-eighth parallel. Concerned about possible intervention by China, the president directed him to keep UN troops away from the Korean-Chinese border. Disregarding the order, MacArthur sent them to within forty miles of China, whereupon 300,000 Chinese soldiers crossed into Korea. With Chinese help, the North Koreans recaptured Seoul.

After three months of grueling battle, UN forces fought their way back to the thirty-eighth parallel. At that point, Truman decided to seek a negotiated settlement. MacArthur was furious when the goal of the war reverted to containment, which to him represented defeat. Taking his case to the public, he challenged both the president’s authority to conduct foreign policy and the principle of civilian control of the military. Fed up with MacArthur’s insubordination, Truman fired him in April 1951. Many Americans sided with MacArthur, reflecting their frustration with containment. Why should Americans die simply to preserve the status quo? Why not destroy the enemy once and for all? Those siding with MacArthur assumed that the United States was all-powerful and blamed the stalemate in Korea on the government’s ineptitude or willingness to shelter subversives.

When Congress investigated MacArthur’s dismissal, all of the top military leaders supported the president. According to the chairman of the Joint Chiefs of Staff, MacArthur wanted to wage “the wrong war, at the wrong place, at the wrong time, with the wrong enemy.” Yet Truman never recovered from the political fallout. Nor was he able to end the war. Negotiations began in July 1951, but peace talks dragged on for two more years while twelve thousand more U.S. soldiers died.