Not sure how much history you've read iconoclastic, but may I suggest that the idea of not targeting civilians during a war is actually the exception rather than the rule for human history. In the Roman world, as in many other time periods, targeting civilians was precisely how war worked. Genocide was a common tool of imperial control. Where genocide wasn't wholesale, it was typically because some elements of the population would have a future of slavery ahead of them.The idea that we're now in some sort of curious epoch of human history because civilians are targeted for violence really doesn't stand up.
More generally, I agree with your point that the bible is very general with those prophesies which have no trace of back-editing. But the bible isn't alone in that. Most 'holy' books share the same approach. And those which don't are those without prophesy.