Bill Moore:

I can't think of a conflict that gets to a point where people kill each other that doesn't involve strong hatred, so I don't see where that has anything much to do with it.

As far as the dreaded nation building goes, that is only part of a good small war fight. The way we do things of course often has next to nothing to do with good practices. Ultimately you have to win over the population, or at least get them stand aside from the fight to the extent they don't support passively or actively the opposition. If you don't do that the only alternative is to get beat or do it the Syrian gov way.