Korean War: President Truman relieves Douglas MacArthur of the command of American forces in Korea and Japan.

The Korean War was an armed conflict on the Korean Peninsula fought between North Korea and South Korea and their allies. North Korea was supported by China and the Soviet Union, while South Korea was supported by the United Nations led by the United States under the auspices of the United Nations Command (UNC). The conflict was one of the first major proxy wars of the Cold War and one of its deadliest conflicts on noncombatants, especially civilians. It is estimated that 1.5 to 3 million Korean civilians were killed during the war. The Korean War was the first time the Security Council of the United Nations (UNSC) authorized the use of force under Chapter VII of the United Nations Charter.