The installation of a new power-sharing government in Northern Ireland in May 2007 was widely welcomed as bringing to an end almost 40 years of intercommunal conflict, and as filling a long-standing political vacuum with a set of new democratic institutions. This article explores the nature of the problem that the new institutions were designed to tackle, outlines the complex blueprint (the Good Friday agreement of 1998) that was designed in response, and assesses the capacity of this constitutional master plan to offer political stability, to prevent a return to paramilitary violence, and to provide a stable channel of expression for the political aspirations of the two communities.