of various commands in the Pacific and Far East. Its origins can be traced to the command structure established early in World War II to wage the war in the Pacific. In April 1942, U.S. military forces in the Pacific Theatre were divided into two commands: the South West Pacific Area (SWPA) under Army General Douglas MacArthur; and the Pacific Ocean Areas (POA) under Navy Admiral Chester W. Nimitz. Each had command of all U.S. military forces assigned to his area. The authority of the POA Commander-in-Chief (CINCPOA) was technically separate from that of the Commander in Chief, Pacific Fleet (CINCPAC), but Admiral Nimitz was assigned to both positions and bore the title CINCPAC/CINCPOA. Efforts to establish a unified command for the entire Pacific AOR proved impossible during the war. The divergent interests of the Army and the Navy precluded the subordination of either of the two principal commanders in the Pacific Theatre. When the war ended in September 1945, the command arrangement carried forward with Fleet Admiral Nimitz as CINCPAC/CINCPOA and General of the Army MacArthur as Commander in Chief, U.S. Army Forces Pacific (CINCAFPAC). Command arrangements after World War II were defined by the "Outline Command Plan"– in a sense, the first Unified Command Plan (UCP)– approved by President Harry S. Truman on 14 December 1946 and authorized by the National Security Act of 1947. The plan called for the establishment of seven unified combatant commands as "an interim measure for the immediate postwar period." The first three unified commands were established in the Pacific. The Joint Chiefs of Staff implementing directive of 16 December 1946 established the Far East Command (FECOM), Pacific Command (PACOM), and Alaskan Command (ALCOM) effective 1 January 1947. The commands, their areas of responsibility, and their missions were as follows: Far East Command: U.S. forces in Japan, Korea, the Ryukyus, the Philippines, and the Mariana and Bonin Islands. The Commander-in-Chief, Far East (CINCFE) would carry out occupation duties, maintain the security of the command, plan and prepare for a general emergency in the area, support the Commander-in-Chief, Pacific (CINCPAC), and command U.S. forces in China in an emergency. Pacific Command: U.S. forces allocated by the Joint Chiefs of Staff within the Pacific Area. CINCPAC would defend the United States against attack through the Pacific, conduct operations in the Pacific, maintain the security of U.S. island positions and of sea and air communications, support