Abstract

The moral dilemma at the heart of the theory of just war stems from the contradiction between two opposing duties: on the one hand, the duty to provide aid, as far as possible, to those whose lives are endangered; and, on the other hand, the duty not to endanger the lives of the innocent. The theory of just war resolves this dilemma, firstly by privileging one of these two duties over the other; and secondly, by imposing conditions on justification concerning the principle of discrimination against civilian populations and the principle of proportionality. The principle of proportionality thus acts as a moral constraint on justification. Nevertheless, the notion of proportion still remains vague. The present paper examines the sense and function of this notion, and analyses the underpinnings of its ethical foundation