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.
Forward air control operations during the Korean War Forward air control operations during the Korean War Forward air controllers in the Korean War were prominent throughout the conflict. United Nations forces depended upon improvised U.S. forward air control systems. The United States military held two competing doctrines for directing close air support (CAS). The U.S. Marine Corps' system depended on an organic supporting air wing delivering ordnance within 1,000 yards of front-line troops; this was to compensate for their weakness in artillery caused by being an amphibious force. On the other hand, the U.S. Army believed close air support should extend the range of its own organic artillery;