Law and Morality at War develops a normative framework within which the law of armed conflict should be evaluated, interpreted, and reformed. The book defends existing protections for civilians, proposes new protections for combatants, and interprets vague and ambiguous rules - including discrimination, precautions, and proportionality - in their morally best light. The book makes original contributions to a variety of current debates in moral and legal philosophy, including the justification of legal authority, moral liability to defensive harm, and moral choice under uncertainty. At the same time, the book directly confronts the complex problems of the modern battlefield, including the use of human shields. Both theoretical and practical, the book aims to better guide combatants and better protect civilians. With a new preface addressing recent developments and continued armed conflict.