United Nations Command
The United Nations Command (UNC) is the unified command structure for the multinational military forces supporting the Republic of Korea (South Korea or ROK) during and after the Korean War. After troops of the Democratic People's Republic of Korea (North Korea or DPRK) invaded South Korea on June 25, 1950, the United Nations Security Council adopted Resolution 82 calling on North Korea to cease hostilities and withdraw to the 38th parallel.
On June 27, 1950, it adopted Resolution 83, recommending that members of the United Nations provide assistance to the Republic of Korea "to repel the armed attack and to restore international peace and security to the area". Security Council Resolution 84, adopted on July 7, 1950, recommended that members providing military forces and other assistance to South Korea "make such forces and other assistance available to a unified command under the United States of America".
President Syngman Rhee of the Republic of Korea assigned operational command of ROK ground, sea, and air forces to General MacArthur as Commander-in-Chief UN Command (CINCUNC) in a letter (the 'Pusan Letter') of July 15, 1950.
On August 29, 1950, the British Commonwealth's 27th Infantry Brigade arrived at Busan to join the UNC, which until then included only ROK and U.S. forces. The 27th Brigade moved into the Naktong River line west of Daegu.
Troop units from other countries of the UN followed in rapid succession; Australia, Belgian United Nations Command, Canada, Colombia, Ethiopia, France, Greece, Luxembourg, the Netherlands, New Zealand, the Philippines, South Africa (No. 2 Squadron SAAF), Thailand, and the Turkish Brigade. Denmark, India, Norway, and Sweden provided medical units. Italy provided a hospital, even though it was not a UN member.
On 1 September 1950 the United Nations Command had a strength of 180,000 in Korea: 92,000 were South Koreans, the balance being Americans and the 1,600-man British 27th Infantry Brigade.
The United Nations Command and the Chinese-North Korean Command signed the Korean Armistice Agreement on 27 July 1953, ending the heavy fighting. The armistice agreement established the Military Armistice Commission (MAC), consisting of representatives of the two signatories, to supervise the implementation of the armistice terms, and the Neutral Nations Supervisory Commission (NNSC) to monitor the armistice's restrictions on the parties reinforcing or rearming themselves. The North Korean-Chinese MAC has been replaced by Panmumjon Representatives under exclusive North Korean management. Regular meetings have been stopped, although duty officers of Joint Security Area, commonly known as the Truce Village of Panmunjom, from each side meet regularly.
Although the resolutions suggested the forces under the UNC were "United Nations forces", and United Nations itself could be considered a belligerent in the war, in practice the United Nations exercised no control over the combat forces, which were controlled by the United States. Most observers concluded that the forces under the UNC were not in law United Nations troops, and the acts of the UNC were not the acts of the United Nations. The UNC can be regarded as an alliance of national armies, operating under the collective right of self-defense. United Nations Security Council Resolution 84 authorized the use of the United Nations flag concurrently with the flags of the participating UNC nations.
In 1994, the UN Secretary General in a letter to the North Korean Foreign Minister distanced the UN from the UNC by writing "the Security Council did not establish the unified command as a subsidiary organ under its control, but merely recommended the creation of such a command, specifying that it be under the authority of the United States. Therefore the dissolution of the unified command does not fall within the responsibility of any United Nations organ but is a matter within the competence of the Government of the United States." 
During the three years of the Korean War, military forces of these nations were allied as members of the UNC. Peak strength for the UNC was 932,964 on July 27, 1953, the day the Armistice Agreement was signed:
- Combat Forces
- Republic of Korea (South Korea) – 590,911
- United States – 302,483
- United Kingdom – 14,198
- Philippines – 7,468
- Thailand – 6,326
- Canada – 6,146
- Turkey – 5,453
- Australia – 2,282
- New Zealand – 1,385
- Ethiopia – 1,271
- Greece – 1,263
- France – 1,119
- Colombia – 1,068
- Belgium – 900
- South Africa – 826
- Netherlands – 819
- Luxembourg – 44
- Humanitarian Aid (not counted in total above)
In early July 1950, amid the confusion of the first days of the war, Seoul placed its armed forces under the command of General Douglas MacArthur as United Nations (UN) commander. This arrangement continued after the armistice. For some twenty-five years, the United Nations Command headquarters, which had no South Korean officers in it, was responsible for the defense of South Korea, with operational control over a majority of the units in the Republic of Korea Armed Forces, the South Korean military. The command was the primary peacetime planning organization for allied response to a North Korean invasion of South Korea and the principal wartime command organization for all South Korean and United States forces involved in defending South Korea.
On November 7, 1978 a binational headquarters, the Republic of Korea – United States Combined Forces Command (CFC), was created, and the South Korean military units with front-line missions were transferred from the UN Command to the CFC's operational control. The commander in chief of the CFC, a United States military officer, answered ultimately to the national command authorities of the United States and the Republic of Korea.
In 1994, all South Korean forces during day to day peacetime conditions (or more properly stated under day to day ongoing Armistice conditions) were returned to the Operational Control of the Republic of Korea. South Korean forces were severed from CFC during the continued Armistice period and the CFC Commander was no longer ultimately responsible for the fighting readiness of South Korean Forces. South Korea, as a sovereign nation, assumed this responsibility.
Under the law, the Commander, United States Forces Korea, is dual-hatted as Commander of the ROK-US CFC. The Deputy Commander is a 4-star general from the ROK Army, who is also dual-hatted as the ground forces component commander.
The CFC has operational control over more than 600,000 active-duty military personnel of all services, of both countries. In wartime, augmentation could include some 3.5 million ROK reservists as well as additional U.S. forces deployed from outside the ROK. If North Korea attacked, the CFC would provide a coordinated defense through its Air, Ground, Naval and Combined Marine Forces Component Commands and the Combined Unconventional Warfare Task Force. In-country and augmentation U.S. forces would be provided to the CFC for employment by the respective combat component. The transfer of wartime control of the defense of South Korea to the South Korean government has been delayed many times with another reconsideration of the current December 2015 target date scheduled for early 2014.
United Nations Command Rear is located at Yokota Air Base, Japan, under a Royal Australian Air Force group captain. It's task is to maintain the SOFA that permits the UNC to retain a logistics rear and staging link on Japanese soil.
- United Nations Memorial Cemetery – in Busan, where 2,300 casualties from various nations are buried.
- United Nations Security Council Resolution 82 PDF, URL retrieved April 9, 2006
- United Nations Security Council Resolution 83 PDF, URL retrieved April 9, 2006
- United Nations Security Council Resolution 84 PDF (bottom half of page), URL retrieved April 9, 2006
- '..In view of the common military effort of the United Nations on behalf of the Republic of Korea, in which all military forces, land, sea and air, of all the United Nations fighting in or near Korea have been placed under your operational command, and in which you have been designated Supreme Commander United Nations Forces, I am happy to assign to you command authority over all land, sea, and air forces of the Republic of Korea during the period of the continuation of the present state of hostilities, such command to be exercised either by you personally or by such military commander or commanders to whom you may delegate the exercise of this authority within Korea or in adjacent seas.'
- Coleman, Bradley Lynn (October 2005). "The Colombian Army in Korea, 1950–1954". The Journal of Military History (Project Muse (Society for Military History)) 69 (4): 1137–1177. doi:10.1353/jmh.2005.0215. ISSN 0899-3718.
- State Deptartment message to DPRK URL retrieved November 29, 2006
- Joint Security Area / Panmunjom URL retrieved April 9, 2006
- Patrick M. Norton (March 1997). Ending the Korean Armistice Agreement: The Legal Issues. Nautilus Institute. Retrieved 21 March 2013.
- Pak Chol Gu (7 May 1997). "Replacement of the Korean Armistice Agreement: Prerequisite to a lasting peace in the Korean Peninsula". Nautilus Institute. Retrieved 2 May 2013. "UN Secretary General Boutros Boutros Ghali noted in his letter to the Foreign Minister of the DPRK, dated 24 June 1994: "I do not believe, though, that any principal organ of the United Nations, including the Secretary General, can be the proper instance to decide on the continued existence or the dissolution of the United Nations Command. However, allow me to recall that the Security Council, in operative paragraph 3 of resolution 84 (1950) of 7 July 1950, limited itself to recommending that all members providing military forces and other assistance to the Republic of Korea 'make such forces and other assistance available to a unified command under the United States of America.' It follows, accordingly, that the Security Council did not establish the unified command as a subsidiary organ under its control, but merely recommended the creation of such a command, specifying that it be under the authority of the United States. Therefore the dissolution of the unified command does not fall within the responsibility of any United Nations organ but is a matter within the competence of the Government of the United States.""
- United Nations Command retrieved June 27, 2011
- Webb, William J. "The Korean War: The Outbreak". United States Army Center for Military History. Retrieved 16 December 2011.
- Eun-jung, Kim (14 October 2013). "S. Korea, U.S. to decide timing of OPCON transfer next year". www.globalpost.com. Yonhap News Agency. Retrieved 14 October 2013.
- Pacific Air Forces, 
- Grey, Jeffrey. The Commonwealth Armies and the Korean War: An Alliance Study. Manchester University Press, 1990.