the failure in your logic...
is to focus on body counts...
There are many things worse than death, and at the same time there are many things worth dying for.
Is this war one of them? Either way that's in the eyes of the beholder.
You are correct in that no simple arithmatic formula can be used to justify this or any other war; however, if you are intellectually honest then no simple arithmatic formula utilizing civilian body counts can be used to conclude that this war was unjustified either...
In other words, we could conceivably kill millions of civilians and the war could still be a Just war...
Such is the world of moral relativism.
Scott