an island territory off the southeastern coast of mainland China. Occupied by Japan between 1895 and 1945, Taiwan came to constitute the Republic of China (ROC), with its own government, following civil war in China in the late 1940s. The mainland became the People’s Republic of China (PRC) in 1949, and it claims Taiwan as part of its territory. When the United States and Japan established formal diplomatic relations with the PRC in the 1970s, they acknowledged the “One China” formulation—Chinese on either side of the Taiwan Strait maintain there is but one China and that Taiwan is a part of China—to manage ties with Taiwan. The Taiwan Relations Act of 1979 requires the United States to provide for the adequate defense of the island; Japan has no such commitment.