Carsten Stahn

The law of armed force is traditionally conceptualized in the categories of jus ad bellum and jus in bello. This dualist conception of armed force has its origin in the legal tradition of the inter-war period. This essay revisits this approach. It argues that the increasing interweaving of the concepts of intervention, armed conflict and peace-making in contemporary practice make it necessary to complement the classical rules of jus ad bellum and in jus in bello with a third branch of the law, namely rules and principles governing peace-making after conflict. The idea of a tripartite conception of armed force, including the concept of justice after war (‘jus post bellum’) has a long-established tradition in moral philosophy and legal theory. This article argues that this historical concept deserves fresh attention from a legal perspective at a time when the contemporary rules of jus ad bellum and jus in bello are increasingly shaped by a normative conception of law and justice and a broadening notion of human security. Moreover, it identifies some of the legal rules and principles underlying a modern conception of ‘just post bellum’.