The "one China" policy officially supported by the People's Republic of China, the United States, and other countries asserts that there is only one China and Taiwan is a part of it. The debate over whether the people of Taiwan are Chinese or independently Taiwanese is, Melissa J. Brown argues, a matter of identity: Han ethnic identity, Chinese national identity, and the relationship of both of these to the new Taiwanese identity forged in the 1990s. In a unique comparison of ethnographic and historical case studies drawn from both Taiwan and China, Brown's book shows how identity is shaped by social experience -- not culture and ancestry, as is commonly claimed in political rhetoric. These case studies document actual changes from non-Han to Han ethnic identity and back again, questioning the PRC's contention that Taiwan is ethnically Han and thus a part of the Chinese nation. Instead, Taiwan bases its claim to difference and singularity on the contributions of plains Aborigines to Taiwanese culture and ancestry. Brown's ethnographic research supports her theory that cultural meanings, social power, and demographic forces constitute distinct, though interacting, systems affecting human behavior and societies. She uses this theoretical framework to analyze possible political policies regarding Taiwan's future and to assess their likely social impacts. With its new approach to identity formation, her work makes an invaluable contribution to the pressing debate over Taiwan's status, and to the construction of a broader and more useful social theory of identity.