Institutionalizing the Just War offers a new approach to thinking about the ethics of large-scale armed conflict. Allen Buchanan takes a unique approach to just war theory, arguing that theories that are content with articulating abstract moral norms specifying right acts of war-making, provide too little guidance for responding to the real world moral problems of war. Buchanan here instead takes an institutional approach, combining moral analysis with data on how institutions are designed, and providing concrete proposals for morally progressive innovations at the institutional level. Buchanan’s institutional approach in this book – which is based on the revision of previously published essays — is singular and will be of great interest not just to scholars of just war theory, but anyone interested in the morality of war within political science, political philosophy, philosophy of international law, and public policy.