the famouse debate between Chomsky and Foucault
Yeah, but surely you believe that your role in the war is a just role, that you are fighting a just war, to bring in a concept from another domain. And that, I think, is important. If you thought that you were fighting an unjust war, you couldn't follow that line of reasoning.
I would like to slightly reformulate what you said. It seems to me that the difference isn't between legality and ideal justice; it's rather between legality and better justice.