ABSTRACT
Jus in bello concerns legitimate conduct in war. One approach, paradigmatic for “revisionist” just war theory, is to decide what is proportionate and which objects or persons constitute legitimate targets by simply relying on the answers given to these questions by ordinary peacetime morality and directly applying them to the case of war. The chapter will demonstrate, however, that the “revisionist” interpretations of peacetime morality – in particular regarding self-defense, necessity, proportionality, lesser evil, double effect, and the relation between justification and liability – are mistaken. This undermines “revisionist” conclusions regarding the ethics of war, not least with respect to the moral equality of combatants. Moreover, the basic approach is misguided anyway. The chapter argues for an alternative approach, which attributes moral force to conventions governing conduct in war. It explains how moral mechanisms based on a principle of reciprocity cause widely accepted laws and conventions to be partly constitutive of the moral rules that apply in a conflict. This means that the moralities of war and peace diverge and that we are not enslaved to a “deep morality” of war but have the moral power – precisely through the customs and laws of war – to partially devise the morality of war.
