The Real Costs of War

Introduction

I believe that the argument presented in the last chapter is a good one and is sufficient to show that far from being supported by JWT, weapons design is actually incompatible with it. It is a good argument because it based on the principle that all wars are evil because of the harms they cause and hence that the only wars that are justified are those whose benefits outweigh their costs – more harms must be seen to be prevented and avoided, as well as reduced, than are caused by the war. This principle must be part of any acceptable account of the morality of war. But is incompatible with weapons design because, as we have seen, weapons design introduces incalculable costs, because it is the way in which new ways to harm come into the world. However, I accept that this argument may not convince everyone, with the suspicion lingering that weapons design which aids the a war which one supposes to be a just one, is justified for that reason alone, regardless of what happens in the future. I maintain, on the contrary, that those future unknowable costs cannot be ignored. If there are other arguments to the effect that wartime weapons research is unjustifiable, then these should also be set down and considered to expel any lingering doubts. And I believe there are two more, both of which are also convincing.

In the last chapter we saw that there are a number of problems with determining the costs and benefits of war in order to make the estimates required by ad bellum proportionality. In fact it looked as if this would not be possible for a war of any significant duration, and it was for this reason that the third of the questions posed in the introduction of the last chapter was given the answer, “Very rarely”. What this means is that in actual practice, a weapons designer will not be able to verify that the general criterion is satisfied at the time when she needs to decide to participate in a weapons design project, even if it turns out that the criterion will be satisfied. But since weapons design is morally wrong, anyone who participates is required to justify her participation at the time: the ‘practical argument against weapons design’, as I will call it, shows that the information that the weapons designer requires to verify that the general criterion is satisfied will not be available when she needs to have it. Having said this, one might wonder whether there is not a small loophole in the practical argument, because it does not take its starting point from the assumption that the costs and benefits of all wars cannot be determined, only that this is ‘very rare’. I believe not, because I believe that the wars for which the estimates of expected costs and benefits look to be plausible and accurate are wars of such limited duration, and are fought by coalitions with overwhelming force on their side, that wartime weapons design is neither necessary nor can be conducted within the available time frame. So while we cannot rule out the possibility that there are wars in which good estimates of the expected costs and benefits can be made, I believe that this does not undermine the practical argument.