U.S.–Japan Alliance

[1] In practice, the commitment to defend Japan from attack includes extending the United States's "nuclear umbrella" to encompass the Japanese isles.

He concentrated upon reconstructing Japan's domestic economy while relying heavily on the security alliance with the United States.

[5] 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.

[6] 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.

[8] However, many Japanese people, especially on the left, but also even some on the center and the right of the political spectrum, preferred to chart a more neutral course in the Cold War,[9] and thus decided to oppose treaty revision as means of expressing their opposition to the U.S.-Japan alliance as a whole.

[10] Kishi and Eisenhower were succeeded by Hayato Ikeda and John F. Kennedy, respectively, who worked to repair the damage to the U.S.-Japan alliance.

[17][18] After the end of the Cold War, Japan is the country with the largest number of U.S. troops outside the United States, approximately 55,000 in 2021.

Japanese and U.S. defense chiefs and diplomats met in Tokyo on 28 July 2024 to enhance military cooperation and missile production amid rising threats from China.

[20] In January 2025, Japan’s Shigeru Ishiba, the Philippines’ Ferdinand Marcos Jr., and the United States’ Joe Biden pledged to deepen their trilateral arrangements due to rising tensions in Asia's waters.