Debates over national identity are a pervasive characteristic of our time. In part, they raise rhetorical questions, but they also have profound implications for American society and American policy at home and abroad. Different perceptions--especially between the citizenry and the more cosmopolitan elites--of what constitutes national identity generate different national interests and policy priorities. The views of the general public on issues of national identity differ significantly from those of many elites. The public, overall, is concerned with physical security but also with societal security, which involves the sustainability--within acceptable conditions for evolution--of existing patterns of language, culture, association, religion...