The is a military alliance between Japan and the United States of America, as codified in the Treaty of Mutual Cooperation and Security between the United States and Japan, which was first signed in 1951, took effect in 1952, and was amended in 1960. The alliance has further been codified in a series of "administrative" agreements, "status of forces" agreements, and secret pacts (密約, mitsuyaku) that have not been subject to legislative review in either country.
Under the terms of the alliance, the United States undertakes to defend Japan in case of attack by a third power, and in return Japan allows U.S. military troops to be stationed on Japanese soil, and makes sizeable "sympathy payments" to underwrite the cost of U.S. bases in Japan. More U.S. military troops are stationed on Japanese soil than in any nation other than the United States. In practice, the commitment to defend Japan from attack includes extending the United States's "nuclear umbrella" to encompass the Japanese isles.
The two nations also share defense technology on a limited basis, work to ensure interoperability of their respective military forces, and frequently participate in joint military exercises.
Although Article 9 of Japan's Constitution forbids Japan from maintaining offensive military capabilities, Japan has supported large-scale U.S. military operations such as the Gulf War, the War in Afghanistan, and the Iraq War with monetary contributions and dispatch of noncombat ground forces.
Formation
The U.S.-Japan alliance was forced on Japan as a condition of ending the U.S.-led military occupation of Japan (1945-1952). The original U.S.-Japan Security Treaty was signed on September 8, 1951, in tandem with the signing of the San Francisco Peace Treaty ending World War II in Asia, and took effect in conjunction with the official end of the occupation on April 28, 1952.
The original Security Treaty had no specified end date or means of abrogation, allowed US forces stationed in Japan to be used for any purpose without prior consultation with the Japanese government, had a clause specifically authorizing US troops to put down domestic protests in Japan, and did not commit the United States to defend Japan if Japan were to be attacked by a third party.
Because the original treaty was so one-sided, it was the target of protests in Japan throughout the 1950s, most notably the "Bloody May Day" protests of May 1, 1952, and Japanese leaders constantly entreated with US leaders to revise it.
The Yoshida Doctrine
The Yoshida Doctrine was a strategy adopted by Japan under Prime Minister Shigeru Yoshida, served from 1948 to 1954. He concentrated upon reconstructing Japan's domestic economy while relying heavily on the security alliance with the United States. The Yoshida Doctrine emerged in 1951 and it shaped Japanese foreign policy into the 21st century. First, Japan is firmly allied with the United States in the Cold War against Communism. Second, Japan relies on American military strength and limits its own defense forces to a minimum. Third, Japan emphasizes economic diplomacy in its world affairs. The Yoshida doctrine was accepted by the United States; the actual term was coined in 1977. The economic dimension was fostered by Hayato Ikeda who served as finance minister and later as prime minister. Most historians argue the policy was wise and successful, but a minority criticize it as naïve and inappropriate.
1950s anti-base protests in Japan
Even after the occupation ended in 1952, the United States maintained large numbers of military troops on Japanese soil. In the mid-1950s there were still 260,000 troops in Japan, utilizing 2,824 facilities throughout the nation (excluding Okinawa), and occupying land totaling 1,352 square kilometres.
The large number of bases and U.S. military personnel produced frictions with the local population and led to a series of contentious anti-base protests, including the Uchinada protests of 1952–1953, the Sunagawa Struggle of 1955–1957, and the Girard incident of 1957.
The growing size and scope of these disturbances helped convince the administration of U.S. President Dwight D. Eisenhower to significantly reduce the number of U.S. troops stationed in mainland Japan (while retaining large numbers of troops in U.S.-occupied Okinawa) and to finally renegotiate the terms of the U.S.-Japan alliance.
1960 treaty revision crisis
In 1960, the government of Japanese prime minister Nobusuke Kishi attempted to pass the revised Security Treaty through the Japanese Diet but was met with mass protests.