This book examines the boundaries of political community by focusing on political membership. By political membership, I mean the principles and practices for incorporating aliens and strangers, immigrants and newcomers, refugees and asylum seekers, into existing polities. Political boundaries define some as members, others as aliens. Membership, in turn, is meaningful only when accompanied by rituals of entry, access, belonging, and privilege. The modern nation-state system has regulated membership in terms of one principal category: national citizenship. We have entered an era when state sovereignty has been frayed and the institution of national citizenship has been disaggregated or unbundled into diverse elements. New modalities of membership have emerged, with the result that the boundaries of the political community, as defined by the nation-state system, are no longer adequate to regulate membership.

Political membership has rarely been considered an important aspect of domestic or international justice. Along with the “invisibility” of state boundaries, the practices and institutions regulating access to and exit from political membership have also been invisible and not subject to theoretical scrutiny and analysis. I want to argue that transnational migrations, and the constitutional as well as policy issues suggested by the movement of peoples across state borders, are central to interstate relations and therefore to a normative theory of global justice.

Recent attempts to develop theories of international and global justice have been curiously silent on the matter of migration (see Pogge 1992; Buchanan 2000; Beitz [1979] 1999 and 2000).