Note: The figures vary by source; peak unit strength varied during war.
The Korean War (25 June 1950 – 27 July 1953)[a] was a war between the Republic of Korea (South Korea), supported by the United Nations, and the Democratic People's Republic of Korea (North Korea), at one time supported by China and the Soviet Union. It was primarily the result of the political division of Korea by an agreement of the victorious Allies at the conclusion of the Pacific War at the end of World War II. The Korean Peninsula was ruled by the Empire of Japan from 1910 until the end of World War II. Following the surrender of the Empire of Japan in September 1945, American administrators divided the peninsula along the 38th parallel, with U.S. military forces occupying the southern half and Soviet military forces occupying the northern half.