The ethics of war explores the moral limits and possibilities of war in its diverse forms. The feasibility of the moral limitation of war is upheld. At the same time, war's fragile moral potential is acknowledged and its causes sought. The argument is conducted from a traditional just war standpoint which balances rules or principles against the moral capacities and dispositions of belligerents and the particular circumstances in which they act. This new and enlarged second edition takes account of recent developments and includes a new section on terrorism and counter-terrorism. A new introduction addresses the common criticism that traditional just war theory is incoherent, outmoded and in need of radical revision. Many of the problems attributed to the tradition by 'revisionists' are seen to derive from a distortion and oversimplification of the historical tradition. A fuller and more accurate understanding of that tradition can mitigate or resolve these problems and help to fill the gaps left in the ethical agenda of war by analytic ethics. Part I compares the conception of just war with realism, militarism and pacifism. Part II examines the principles of just recourse and just conduct with the aid of real life examples. A new Part III discusses the propriety of defining terrorism and the ethical problems raised by particular aspects of terrorism and counter-terrorism, such as the tension between moral and strategic concerns, the variable moral impact of different forms of terrorism, the status and the moral disposition of the terrorist, the treatment of non-combatants, the resort to preventive war and interrogational torture and the use of drones and risk-free warfare. The ethics of war will appeal to both an academic and professional readership in the ethics of war and just war thinking. It will be of particular interest to students and faculty in applied ethics, philosophy, politics, international relations and war studies, but also military practitioners and policy-makers.