Citizenship presents two faces. Within a political community it stands for inclusion and universalism, but to outsiders, citizenship means exclusion. Because these aspects of citizenship appear spatially and jurisdictionally separate, they are usually regarded as complementary. In fact, the inclusionary and exclusionary dimensions of citizenship dramatically collide within the territory of the nation-state, creating multiple contradictions when it comes to the class of people the law calls aliens--transnational migrants with a status short of full citizenship. Examining alienage and alienage law in all of its complexities, The Citizen and the Alien explores the dilemmas of inclusion and exclusion inherent in the practices and institutions of citizenship in liberal democratic societies, especially the United States. In doing so, it offers an important new perspective on the changing meaning of citizenship in a world of highly porous borders and increasing transmigration.

As a particular form of noncitizenship, alienage represents a powerful lens through which to examine the meaning of citizenship itself, argues Linda Bosniak. She uses alienage to examine the promises and limits of the "equal citizenship" ideal that animates many constitutional democracies. In the process, she shows how core features of globalization serve to shape the structure of legal and social relationships at the very heart of national societies.