Britannica Sources used in this answer

Why did the United Nations intervene in the Korean War?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Korean War, June–August 1950 — Korean War Map showing North Korean advances in the Korean War in June–August 1950.

The United Nations intervened in the Korean War primarily to condemn the North Korean invasion of South Korea and to restore peace to the region.1

Following the invasion in June 1950, the United Nations Security Council passed a resolution calling upon member nations to provide necessary assistance to South Korea to repel the aggression. This action was made possible because the Soviet Union, which would have likely vetoed the measure, was boycotting the council at the time to protest the lack of representation for the People’s Republic of China in the United Nations.1

In response to the UN’s call, a unified command was established under the leadership of U.S. General Douglas MacArthur. While sixteen member countries contributed armed forces, the United States provided the majority of the military personnel, supplies, and financial support to defend South Korea. Later, in October 1950, the UN General Assembly authorized forces to advance into North Korea to pursue the destruction of North Korean armed forces and to facilitate the unification of the country.21