Korean reunification selected the 38th parallel as a dividing line. Japanese troops to the North of this line were to surrender to the Soviet Union and troops to the South of this line would surrender to the United States. This was not originally intended to result in a long-lasting partition, but Cold War politics resulted in the establishment of two separate governments in the two zones in 1948 and rising tensions prevented cooperation. The desire of many Koreans for a peaceful unification was dashed when the Korean War broke out in 1950. In June 1950, troops from North Korea invaded South Korea.
Soviet Union in the Korean War China. By April 1950, the Soviet Union had provided 63 of the North Korean Air Force's 178 aircraft, which until September 1950 proved highly effective against minimal South Korean air defenses (which was more heavily backed by US and UN air forces instead) An important area in which Soviet intervention was key in the Korean War was in the air-war. Soviet innovation in aircraft design, as well as the experience of many of its pilots following the Second World War meant that the 'new' states of China and North Korea were dependent on Soviet help in this area. Both the