John Haldane says there are two ways to look at it.
Yes, I mean, we can look at the question of just war from sort of two perspectives. One is as it were would be, when have you got a license to go to war, right – so that’s as it were the thought that, you know, war is basically speaking a kind of reasonable strategy or a reasonable measure in human life, but it may just have to be constrained under certain circumstances and so you’re just having to check that you’re … you know, you’ve ticked the sort of boxes and it’s ok to go.
But the other view would be to say, no, the point is that war is exceptional, I mean, the presumption is against war – that other things being equal, war is evil. So the point is, you’re going to have to show that there are special circumstances that mean that this general prohibition is lifted.
Now I would say that the tradition of the just war has been not a tradition of issuing licenses to go to war – or at least theoretically it hasn’t been that – it’s been rather giving permission in extreme circumstances to use violence. But it’s … the background presumption is that war is wrong, and so you’ve got to make a very strong case, you’ve got to get over the threshold, to show that it would be permissible in some circumstances, rather than that war is ok as long as you don’t do these things.