During the Korean War, US-Japan relations changed dramatically from the occupation status into one of a security partnership in Asia. When North Korea invaded South Korea, Washington perceived Japan as the ultimate target. Washington immediately intervened in the Korean peninsula to protect the South on behalf of Japanese security. Japanese security was the most important objective of American policy regarding the Korean War, a reality to which historians have not given legitimate attention. While fighting in Korea, Washington decided to conclude an early peace treaty with Japan to initiate Japanese rearmament. The issue of Japanese rearmament was a focal point in the Japanese peace negotiation. Washington pressed Japan to rearm rapidly, but Tokyo stubbornly opposed. Under pressure from Washington, the Japanese government established the National Police Reserve and had to expand its military forces during the war. When the Korean War ceased in July 1953, Japanese armed forces numbered about 180,000 men. The Korean War also brought a fundamental change to Japanese economic and diplomatic relations in Asia. With a trade embargo on China following the unexpected Chinese intervention in Korea, Washington wanted to forbid Sino-Japanese trade completely. In addition, Washington pressed Tokyo to recognize the Nationalist regime in Taiwan …