The Korean War

The decade after World War Two saw communism spreading to the Far East. While China became communist in 1949, it was the conflict in Korea that proved to be the biggest crisis for relations between the USA and the USSR in the 1950s.

The success of communism in China had persuaded the USA that their domino theory was correct. This suggested that if one country was allowed to fall to communism then communism could quickly spread to neighbouring countries. In 1950 a report by the American National Security Council recommended that the policy of containment was not enough, and that what was needed was ‘roll back’ or action to take back territory from communist control.

What caused the Korean war?

After World War Two, Korea had been divided at the 38th parallel into the Soviet-backed communist North Korea, led by Kim Il Sung, and non-communist, American-backed South Korea under the leadership of Syngman Rhee.

In June 1950, with the support of China and the Soviet Union, North Korea launched an attack on South Korea across the 38th parallel.

America and the UN to the rescue

Image of US troops emerging from helicopters during the Korean war in 1953

  1. June 1950: The North Korean People’s Army advanced quickly and pushed the Southern forces to a small area around Pusan in South Korea.
  2. July 1950: Fearing a communist takeover, the USA sent troops to support South Korea.
  3. The USA appealed to the United Nations for help and its Security Council agreed to the request. The resolution was passed as the Soviets were boycotting the United Nations in protest at the Chinese communist government not being allowed to take its seat at the Security Council.
  4. September 1950: UN forces, led by the American General MacArthur, landed in Inchon and quickly pushed the North Koreans back over the 38th parallel and by October 1950 they had almost ‘rolled back’ the communists to the Yalu River on the border with China.
  5. October 1950: Not wanting a US-backed state on its border, China invaded Korea and drove the UN forces back below the 38th parallel. General MacArthur called for the use of atomic weapons but this was denied by President Truman and MacArthur was sacked.
  6. June 1951: More UN troops were deployed to Korea and the communists were eventually driven back to the 38th parallel.
  7. July 1953: An armistice was finally signed at Panmunjom on the 38th parallel which left Korea divided as it had been in 1950 and still is today.
A series of maps showing the progression of the Korean War

Impact and consequences of the Korean War

The Korean War was an important development in the Cold War because it was the first time that the two superpowers, the United States and the Soviet Union, had fought a ‘proxy war’ in a third country. The proxy war or 'limited war' strategy would be a feature of other Cold War conflicts, for example the Vietnam War. It also established a precedent of the USA being involved in events in Asia.

Even when the fighting had stopped, American soldiers remained stationed in South Korea which was a worry for the Chinese and put pressure on relations between the two countries.