Why was the Korean war a threat to world peace?

Answer 1

It was feared that the United States would attack Communist China directly to stem the flow of Chinese fighting along side the North Korean army. The Chinese would then call on their Communist allies, the Soviet Union, to help the Chinese. The Soviets would then intervene either directly in China, or in a move to draw the United States off balance, the Soviets would launch an attack against perhaps Europe or Japan. In addition, it could not be certain if the United States or the Soviets would go nuclear in such an exchange. Thus, the Korean War could have turned into World War III. However, to forstall that, United States President Harry S Truman did not escalate the Korean "police action". Indeed, President Truman fired General Douglas MacArthur to ensure it did not happen. It was General MacArthur who advocated taking the battle to the Communist Chinese in their own country.