1) Before World War 2, Korea had been invaded by both China and Japan throughout its history and was split along the 38th parallel after WWII, with the Soviet-backed North and the democratic South. 2) In June 1950, North Korea invaded South Korea in an attempt to reunify the country by force under communist rule. 3) After initial setbacks, United Nations forces led by the United States pushed North Korea back above the 38th parallel and advanced towards the Chinese border, but peace talks began in 1951 and a ceasefire was signed in 1953, leaving the division of Korea along the original border.