The reestablishment of Japanese defense forces has been a subject of heated debate in the period since World War II. Article 9 of the constitution renounces war as a sovereign right and the maintenance of "land, sea and air forces, as well as other war potential." During the Korean War, General MacArthur recommended the establishment of a national police reserve. Following the signing of the San Francisco Peace Treaty, the reserve force was reorganized into a National Safety Agency (1 August 1952). Laws establishing a Defense Agency and a Self-Defense Force became effective on 1 July 1954, both under firm civilian control.
The strength of Japan's armed forces in 2002 was 239,900 active personnel including some 10,400 women. The Ground Self-Defense Force had 148,200 personnel, organized into one armored and 10 infantry divisions. There were also 47,000 personnel in reserve components. The Maritime Self-Defense Force, consisting of 44,400 personnel, had 54 surface combatants, 16 combat submarines, and an air arm of about 80 combat aircraft and 90 armed helicopters. Air Self-Defense Force personnel numbered 45,600 with combat aircraft totaling 280. Japan has a paramilitary coast guard of 12,250 operating 333 patrol vessels.
Although Japan's defense budgets—about $41 billion in 2001—rank high by world standards, they are modest in relation to gross domestic product (about 1%). The US maintains extensive military facilities and 40,000 troops in Japan. Japan participates in peacekeeping missions in East Timor and the Middle East.