In my previous writings I have argued that the justice of initiating war, jus ad bellum, should be understood as having limits based on certain considerations of the justice of tactics and strategies of war, jus in bello, such as whether a war is likely to be fought in ways that violate the principle of discrimination or distinction. In the current chapter I argue that the justice of initiating war should also take into account certain considerations of the justice after war ends, jus post bellum, such as whether war is likely to result in such serious devastation that it makes it very likely that the principles of rebuilding and reparations will be violated. Very little good work has been done on jus post bellum principles, until quite recently, and even less good work has been done on how jus post bellum considerations relate to the other two branches of the just war tradition.

The development of increasingly sophisticated and destructive weapons means that how war is likely to be conducted, and especially how destructive the war will be, should affect the justice of whether to initiate war in the first place. I will use this particular debate as a jumping-off point for looking at how jus post bellum principles, already discussed in detail in earlier chapters, might influence jus ad bellum principles. With the increased destructiveness of war come worries about whether and to what extent States will be able to rebuild after a war ends. As has been recognized for centuries, highly destructive wars are generally not likely to lead to a just and lasting peace.