page_title: Foreign policy of the Harry S. Truman administration
section_title: Outbreak of the war
hierarchical_section_title: Foreign policy of the Harry S. Truman administration / Korean War / Outbreak of the war
caption_attribution_description: President Harry S. Truman is shown at his desk at the White House signing a proclamation declaring a national emergency.
context_page_description: The foreign policy of the Harry S. Truman administration was the foreign policy of the United States from April 12, 1945 to January 20, 1953, when Harry S. Truman served as the President of the United States. The Truman administration's foreign policy primarily addressed the end of World War II, the aftermath of that war, and the beginning of the Cold War. Truman's presidency was a turning point in foreign affairs, as the United States engaged in an internationalist foreign policy and renounced isolationism.
  Truman took office upon the death of Franklin D. Roosevelt during the final year of World War II. Truman had not generally shown a strong interest in foreign affairs prior to taking office, and as president he relied heavily on advisers like George Marshall and Dean Acheson, both of whom served as Secretary of State under Truman. Nazi Germany surrendered shortly after Truman took office, but the Empire of Japan initially refused to surrender. In order to force Japan's surrender without resorting to an invasion of the main Japanese islands, Truman approved of the military's plans to drop atomic bombs on two Japanese cities.
context_section_description: Following World War II, the United States and the Soviet Union occupied Korea, which had been a colony of the Japanese Empire. The 38th parallel was chosen as a line of partition between the occupying powers since it was approximately halfway between Korea's northernmost and southernmost regions, and was always intended to mark a temporary separation before the eventual reunification of Korea. Nonetheless, the Soviet Union established the Democratic People's Republic of Korea (North Korea) in 1948, while the United States established the Republic of Korea (South Korea) that same year. Hoping to avoid a long-term military commitment in the region, Truman withdrew U.S. soldiers from the Korean Peninsula in 1949. The Soviet Union also withdrew their soldiers from Korea in 1949, but continued to supply North Korea with military aid.
  On June 25, 1950, Kim Il-sung's Korean People's Army invaded South Korea, starting the Korean War. In the early weeks of the war, the North Koreans easily pushed back their southern counterparts. The Soviet Union was not directly involved, though Kim did win Stalin's approval before launching the invasion. Truman, meanwhile, did not view Korea itself as a vital region in the Cold War, but he believed that allowing a Western-aligned country to fall would embolden Communists around the world and damage his own standing at home. The top officials of the Truman administration were heavily influenced by a desire to not repeat the "appeasement" of the 1930s; Truman stated to an aide, "there's no telling what they'll do, if we don't put up a fight right now." Truman turned to the United Nations to condemn the invasion. With the Soviet Union boycotting the United Nations Security Council due to the UN's refusal to recognize the People's Republic of China, Truman won approval of Resolution 84. The resolution denounced North Korea's actions and empowered other nations to defend South Korea.
  North Korean forces experienced early successes, capturing the city of Seoul on June 28. Fearing the fall of the entire peninsula, General Douglas MacArthur, commander of U.S. forces in Asia, won Truman's approval to land U.S. troops on the peninsula. Rather than asking Congress for a declaration of war, Truman argued that the UN Resolution provided the presidency the constitutional power to deploy soldiers as a "police action" under the aegis of the UN. The intervention in Korea was widely popular in the United States at the time, and Truman's July 1950 request for $10 billion was approved almost unanimously. By August 1950, U.S. troops pouring into South Korea, along with American air strikes, stabilized the front around the Pusan Perimeter.  Responding to criticism over unreadiness, Truman fired Secretary of Defense Louis Johnson and replaced him with the George Marshall. With UN approval, Truman decided on a "rollback" policy—conquest of North Korea. UN forces launched a counterattack, scoring a stunning surprise victory with an amphibious landing at the Battle of Inchon that trapped most of the invaders. UN forces marched north, toward the Yalu River boundary with China, with the goal of reuniting Korea under UN auspices.
caption: President Truman signing a proclamation declaring a national emergency and authorizing U.S. entry into the Korean War
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