After the North Korean invasion in 1950, the United States secured UN support to defend South Korea. Which conflict does this describe?

• A. World War II
• B. Korean War
• C. Gulf War
• D. Vietnam War

Answer: (B)

This describes the Korean War, a mid‑century conflict sparked when North Korea invaded South Korea in 1950 and the United States led a United Nations–backed defense of the South. When the invasion occurred, the UN Security Council authorized collective military action to repel the North, and the United States headed the multinational force under that mandate. The fighting lasted from 1950 to 1953, featuring dramatic moves like the Inchon landing and a push into the North, followed by Chinese involvement and a grueling stalemate near the original boundary. An armistice in 1953 established the Korean Demilitarized Zone, but no formal peace treaty was signed.

This differs from World War II, which ended in 1945 and involved a global Allied effort against the Axis powers. It also differs from the Gulf War, which began in response to Iraq’s invasion of Kuwait in 1990. And it’s distinct from the Vietnam War, a prolonged conflict in Southeast Asia beginning in the 1950s–1960s with different causes and dynamics, not a UN‑led defense against an invasion of Korea.