•The first phase began on June 25, 1950 and ended on the day United Nations (U.N) forces thrust into North Korea's territory.
The unexpected decision of China's entry into the war in early October turned the tide of the war. The Northern units, consisting of Sino-Korean troops, sent the U.N forces retreating again. On December 6, the Communist forces retook Pyongyang. And by the end of December, they re-crossed the parallel and retook Seoul.
States stalled negotiations and in a bid to intimidate North Korea and to end the war quickly, the use of nuclear weapons were considered. The armistice was finally signed on July 27, 1953.
China had become Communist in 1949 and this really worried the Americans. They were worried that Communism was spreading throughout the world, the existence of COMINFORM seemed to confirm this.
Technically American troops weren’t fighting the Korean War. The United Nations sent troops from its member states to ‘keep peace’. As America was the most important and richest country in the U.N. it sent the most troops and supplied most of the weapons. In reality America dominated the U.N. and influenced its allies into supporting what it was doing in Korea.
The USA learnt that there were risks associated with the policy of containment. Over one million people died in the war and what started out as confrontation with North Korea quickly got out of hand when China, the country with the worlds largest army,
prepared to die for Communism. They also had modern weapons supplied by the USSR.