What caused the Korean War?

• A. South Korea invaded North Korea in 1950
• B. North Korea invaded South Korea in 1950
• C. China invaded Korea
• D. UN forces invaded Korea

Answer: (B)

The main idea is that the war began when North Korea invaded South Korea in 1950, attempting to reunify the peninsula under a communist government. After Korea was divided at the 38th parallel following World War II, the North, backed by the Soviet Union, and the South, backed by the United States, remained in deep political and military tension. When diplomacy failed, North Korea launched a large-scale invasion across the border in June 1950, pushing southward and catching South Korean forces off guard. That invasion was the direct trigger for the fighting. The United Nations then intervened to defend South Korea, and China later entered the war on the North’s side. The other statements don’t fit because they describe actions that happened later or were not the initial cause of the conflict.