Abstract
This chapter explores the ongoing debate in the ethics of war between the traditional collectivist accounts of war, and revisionist reductive individualist accounts. I begin by reflecting on the ethics of war as a domain of applied philosophy. I then outline the origins of the Western just war tradition, and set out the central tenets of the collectivist view: that war is an irreducibly collective enterprise that must be morally judged on its own terms. I then explain how this traditional view has been challenged by reductive individualism, and consider the prospects of reductive individualism as an alternative theory of the just war.