U.S. policy toward Taiwan is unique. Since both the Chinese governments on Taiwan and on mainland China held that they alone were China's legitimate ruling government, U.S. diplomatic relations with Taiwan had to be severed in 1979 when the United States recognised the People's Republic of China (PRC) government as China's sole legitimate governments. While maintaining diplomatic relations with the PRC, the United States maintains extensive but unofficial relations with Taiwan based on the framework of the 1979 Taiwan Relations Act. U.S. interests in Taiwan include significant commercial ties, objections to PRC military threats against Taiwan, arms sales and security assurances, and support for Taiwan's democratic development. This book examines the historical background of Taiwan; its political status, relations with China; and the implications for U.S. policy.