Walton Walker backed South Korea, and China allied with the Soviet Union in what was to become the first military action of the Cold War. Shortly after 75,000 North Korean troops with tanks invaded South Korea on June 25, 1950, American air and sea forces were ordered by President Harry S. Truman to give South Korean troops support. The U.S. Eighth Army was ordered to intervene and drive the invaders back across the 38th parallel, the border between the two countries. With only four lightly equipped and poorly trained divisions, Walker began landing troops on the southeast side of the Korean peninsula
North Korea–South Korea relations led to the formation of the United Nations Temporary Commission on Korea (UNTCOK) in 1947. The Soviet Union opposed this move and refused to allow UNTCOK to operate in the North. UNTCOK organised a general election in the South, which was held on May 10, 1948. The Republic of Korea was established with Syngman Rhee as President, and formally replaced the US military occupation on August 15. In North Korea, the Democratic People's Republic of Korea was declared on September 9, with Kim Il-sung, as prime minister. Soviet occupation forces left the North on December 10, 1948. US forces left