Elad Uzan

Much of revisionist just war theory is individualistic in nature: morality in war is just an extension of morality in interpersonal circumstances, so that killing in war is subject to the same moral principles that govern personal self-defense and defense of others. Recent work in the ethics of self-defense suggests that this individualism leads to a puzzle, which I call the puzzle of aggregation, when many threateners contribute to a single threatened harm. In this paper, I investigate the moral problems posed by the puzzle of aggregation and develop a novel account recently proposed by Jeff McMahan, which he calls “proportionality in the aggregate”. I argue that accepting proportionality in the aggregate as a moral constraint on the use of force has significant implications for the ethics of war and self-defense.

In response to foreign interference in elections, warlike language is understandable. As a hostile violation of sovereignty, election meddling fits one technical description of an invasion. However, just war theory, the most influential source of objective guidance for the ethical prosecution of wars, and the philosophical heart of international law concerning war, offers a sobering rejoinder. The theory suggests that, while election meddling is in fact a belligerent act, no actual use of military force could ever be ethically justified as a response.

The problem of moral sunk costs pervades decision-making with respect to war. In the terms of just war theory, it may seem that incurring a large moral cost results in permissiveness: if a just goal may be reached at a small cost beyond that which was deemed proportionate at the outset of war, how can it be reasonable to require cessation? On this view, moral costs already expended could have major implications for the ethics of conflict termination. Discussion of sunk costs in moral theorizing about war has settled into four camps: Quota, Prospect, Addition, and Discount. In this paper, I offer a mathematical model that articulates each of these views. The purpose of the mathematisation is threefold. First, to unify the sunk costs problem. Second, to show that these views differ in the nature of their justifications: some are justified qualitatively and others quantitatively. Third, to clarify the differential force of qualitative and quantitative critiques of these four views.