With the occupation from 1945 to 1952, the United States assumed responsibility for the island nation's defense. In 1969, the two governments signed the Treaty of Mutual Cooperation and Security, providing the basis for close defense ties. Today, about 47,000 U.S. troops are stationed in Japan, including about 28,000 on Okinawa. Headquarters, U.S. Forces Japan is at Yokota Air Base, about 25 miles west of Tokyo. Japan's self-defense forces are primarily responsible for defending Japan's homeland, territorial seas and skies.
Japan has forsworn nuclear arms and forbids arms sales abroad.
Japan defrays the costs of maintaining U.S. forces as well as the cost of bilateral planning, training and exercises. In 1996, President Clinton and Japan's Prime Minister Hashimoto signed the U.S.-Japan Joint Declaration on Security, reaffirming continuing commitment to the security alliance.