Historic region consisting of North Korea and South Korea; peninsula off northeastern China separating the Yellow Sea and Sea of Japan, two arms of the Pacific Ocean.
Note: Korea was under Japanese rule in the early twentieth century. At the end of World War II, Korea was divided at the thirty-eighth parallel of north latitude into two zones, with troops of the Soviet Union in the north and troops of the United States in the south. By 1948, two separate governments had emerged, the communist Democratic People's Republic of Korea in the north and the noncommunist Republic of Korea in the south. American and Soviet troops were withdrawn by 1949. The Korean War (1950–1953) began when North Korean forces invaded South Korea. Forces of the United Nations under General Douglas MacArthur aided South Korea, whereas Chinese forces aided North Korea.