The postwar constitution prohibits Japan to maintain military forces and to lead war for settling international disputes.
Despite the anti-war clause, the National Police Reserve was established in 1950 during the occupation of Japan by the Allied powers (1945-1952) as a replacement for American troops, sent into the Korean War. The National Police Reserve was transformed into the Self Defense Force (SDF) by the Japanese government in 1954.
The Self Defense Force is divided into three branches:
- Ground Self Defense Force
- Maritime Self Defense Force
- Air Self Defense Force
The Self Defense Force's purpose is to preserve peace, public order and Japan's independence and safety. About 6% of the national budget is spent on national defense (2005). Military service is voluntary. The force has about 250,000 members. Supreme commander is the Prime Minister.
