After World War II, Korea was divided at the 38th parallel into a Soviet-backed North and an American-backed South.

In June 1950, North Korean forces, with the support of the Soviet Union and China, launched a full-scale invasion of South Korea.

The United States, acting under the banner of the United Nations, intervened to defend South Korea.

This was the first major military conflict of the Cold War, transforming it from a political to a military confrontation.

A U.N. force, led by U.S. General Douglas MacArthur, launched a successful amphibious landing at Inchon that turned the tide of the war.

As U.N. forces pushed deep into North Korea, China entered the war on a massive scale, pushing the U.N. forces back south.

The war then settled into a bloody stalemate roughly along the original 38th parallel boundary.

The fighting ended in 1953 with the signing of an armistice, but no formal peace treaty was ever signed.

The war resulted in millions of casualties and left the Korean peninsula permanently divided.

The Korean War demonstrated the willingness of the superpowers to fight proxy wars in third countries.