The way I see it, sure we go in and eradicate a few terrorists, but everyone else in that country watches and see us going in and blowing stuff up. So we go in and try to wipe out all the "bad" in one of those countries, then the surrounding countries see us just coming to the region and systematically blowing up each country, one by one. This is a self perpetuating cycle and every time we go there and blow more stuff up, we give many times the original amount of people we went to kill a reason to want to kill us. Somehow it's got to stop. I think in some cases we do have to proactively go after "terrorists", but this has to be thought about long and hard and going after "any threat" is precisely what keeps perpetuating the threat IMO.