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
United States Air Force In South Korea North Korean forces largely removed from the South, the United Nations decided to enforce its prewar intention of reuniting all of Korea under one government, and UN forces advanced across the 38th parallel and into North Korea in early October 1950. However, the decision to cross the 38th Parallel appears, in retrospect, to have been the turning point in the Korean War. On 1 October Chinese Premier Chou En-lai warned that China would not tolerate or stand aside if UN forces invaded North Korea. This was a clear threat that China would intervene if that should happen. On the second