Answer:
In June 1950 communist North Korea invaded South Korea. The United States came to the aid of South Korea at the head of a United Nations force composed of more than a dozen countries. Communist China joined North Korea in the war in November 1950, unleashing a massive Chinese ground attack against American forces.
Explanation: The original agreement and intent was to create a unified and independent Korea out of the post Japanese occupation era. Instead each side of the 38th parallel established its own government under the influence of the occupational country; the United States in South Korea and the Soviet Union in North Korea.