Published in the Review of International Studies in 2011, this article starts by considering the academic and policy debate on state failure since the early 1990s. Since then, its empirical and analytical sophistication has grown, yet the fact that state failure is a regional phenomenon, that is, that it occurs in clusters of geographically contiguous states, has largely been overlooked. This article first considers the academic and policy debates on state failure in the Political Science/International Relations and Development Studies literatures, and offers a definition of state failure that is derived from the means of the state, rather than its ends. Subsequently engaging with existing scholarship on the concept of “region” in international security, the article develops a definition of “state failure regions”. Further empirical observation of such regions and additional conceptual reflections lead to establishing an analytical model for the study of state failure regions and allow identifying a number of concrete gains in knowledge and understanding that can result from its application.