This chapter is concerned with the necessity constraint on defensive harming. It first considers whether a defensive option that would cause more harm than some other equally effective option is ruled out as causing unnecessary harm. The chapter argues that it is not. It defends the view, nonetheless, that there is a sense of “necessary” and a sense of “proportionate” such that defensive liability is itself limited to necessary and proportionate harm. The remainder of the chapter defends the view that (...) necessity, effectiveness, and proportionality are all “internal” to liability—that is, that one cannot be liable to suffer harm that is unnecessary ineffective or disproportionate. (shrink)

It is generally agreed that using lethal or otherwise serious force in self-defense is justified only when three conditions are satisfied: first, there are some grounds for the defender to give priority to his own interests over those of the attacker (whether because the attacker has lost the protection of his right to life, for example, or because of the defender’s prerogative to prefer himself to others); second, the harm used is proportionate to the threat thereby averted; third, the harm (...) is necessary to avert that threat. The first and second conditions have been exhaustively discussed, but the third has been oddly neglected. Meanwhile a prominent school of thought has arisen, in the ethics of war, which seeks to ground the justification of killing in war in principles of individual self-defense. They too have failed to offer any substantive analysis of necessity, while at the same time appealing to it when it suits them to do so. In this paper, I attempt a detailed analysis of the necessity constraint on defensive force, and explore the implications of that analysis for the attempt to transpose principles of individual self-defense into the context of warfare. (shrink)

to appear in Larry May, ed., War and Political Philosophy (Cambridge: Cambridge University Press).

In this article, I develop a general explanatory model of the liability and lesser evil justifications of harm. Despite their respective provenance in consequentialist and deontological ethics, both justifications are, at root, rich forms of the proportionality relationship between a shared set of underlying normative variables. The nature of the proportionality relationship, and the conditions under which it operates, differ between the two forms of justification. The article explores these differences in detail and the implications they have for the justification (...) of self-defense and war. (shrink)

Because the poorest people tend to die from easily preventable diseases, addressing poverty is a relatively cheap way to save lives. War, by contrast, is extremely expensive. This article argues that, since states that wage war could alleviate poverty instead, poverty can render war unjust. Two just war theory conditions prove relevant: proportionality and last resort. Proportionality requires that war does not yield excessive costs in relation to the benefits. Standardly, just war theorists count only the direct costs: the death (...) and destruction wrought by war. This article argues that it can sometimes be appropriate to add the opportunity costs of a failure to alleviate poverty. Last resort is the condition that there must be no better alternative means of achieving the same just end for which the war is waged. This article argues that there are some cases in which alleviating poverty may constitute a better alternative. These are cases in which the most fitting description of the just end for war is sufficiently general that poverty alleviation offers a means to pursue it. The idea that poverty can sometimes render war unjust has, to date, been largely overlooked. It is, nevertheless, an idea with profound implications since, once taken seriously, war becomes much harder to justify. Wars that, in every other respect, seem just may prove disproportionate or unnecessary given the alternative of alleviating poverty. (shrink)