The USA decides to send troops to fight in the Korean War.

On June 27, 1950, President Harry S. Truman announces that he is ordering U.S. air and naval forces to South Korea to aid the democratic nation in repulsing an invasion by communist North Korea. The United States was undertaking the major military operation, he explained, to enforce a United Nations resolution calling for an end to hostilities, and to stem the spread of communism in Asia. In addition to ordering U.S. forces to Korea, Truman also deployed the U.S. 7th Fleet to Formosa (Taiwan) to guard against invasion by communist China and ordered an acceleration of military aid to French forces fighting communist guerrillas in Vietnam.

At the Yalta Conference towards the end of World War II, the United States, the USSR, and Great Britain agreed to divide Korea into two separate occupation zones. The country was split along the 38th parallel, with Soviet forces occupying the northern zone and Americans stationed in the south. In 1947, the United States and Great Britain called for free elections throughout Korea, but the Soviets refused to comply. In May 1948 the Korean Democratic People’s Republic–a communist state–was proclaimed in North Korea. In August, the democratic Republic of Korea was established in South Korea. By 1949, both the United States and the USSR had withdrawn the majority of their troops from the Korean Peninsula.