# North Korean of North Korea. A reference to the Korean War, fought in the early 1950s between the United Nations and communist North Korea (the northern half of the peninsula off northeastern China). The war began in 1950 when North Korea invaded South Korea. The United Nations declared North Korea the aggressor and sent troops, mostly from United States forces, to aid the South Korean army. In 1953, with neither side having a prospect of victory, a truce was signed.