A constitution introduced during the Allied occupation after World War II, with the emphasis placed on the dismantling of militarism and the extension of individual liberties. Drafted under US influence, it was finally adopted on 3 may 1947. The constitution left the emperor as head of state but stripped him of governing power, vesting legislative authority in a bicameral Diet, the lower House of Representatives (originally 466, now 480 seats) being elected for four years and the upper House of Councillors (242 seats) for six (half at a time at three-year intervals). Executive power is vested in the cabinet, which is headed by a Prime Minister and is responsible to the Diet. The constitution specifically renounces war but has been interpreted as allowing self-defence: accordingly, Self Defence Forces have been created, although defence expenditure remains low by Western standards. In 1992 legislation was finally passed allowing Japan’s Self Defence Forces to serve overseas in UN peacekeeping operations.