This volume is about the discourse and practice of intervention and non-intervention in international relations. The product of a dialogue between theorists of politics and international relations, it argues that intervention is endemic in world politics but that we need to move beyond traditional accounts of such practices. In moving towards a more encompassing approach, it explores traditional and post-modern perspectives on our understanding of sovereignty, the state and the state system; conceptions of power, identity and agency; and universal, particularist and contingent justifications for intervention and non-intervention.