In the end someone is going to have to resolve the Sunni Shia conflict and that is going to involve talking to whoever represents them. You may not have noticed but bombing the crap out of these areas isn't working very well as a long term policy.

And how do you propose that we try to reason with people whose only goal is to kill us and who don't mind dying in the process? Perhaps you would like to go over there and try talking to them. Personally, I prefer to keep my head where it is...