This special issue of International Studies Review focuses on the "Westphalian Moment" when the modern system of territorially organized states is said to have come into existence. The authors examine a number of issues relating to sovereignty in both its internal and external manifestations, including the role of norms in undermining non-sovereign forms of political organization, manifestations of exclusive authority over territory before Westphalia, the relationship between regional organizations and sovereign states, and the role of environmental interdependence in undermining sovereign institutions.

James A. Caporaso is a professor in the Department of Political Science at the University of Washington.