They are people looking for a cause and very vulnerable to falling for the terrorist schtick. I think we can do better than we have been doing- but that would actually take some effort. Fighting terrorism is different that fighting an actual war- the "Cut off the head and the snake dies" axiom doesn't work. You neuter them by cutting off what they add to their numbers with.
How do you do that? Well, I really don't know, but you would think with all of the big minds we have in the military, FBI and CIA, they could come up with something effective. Committing attrocities against people you fight against doesn't solve the problem, it accelerates it.
Democracy building is worthless. The government we constructed will be overthrown shortly after we leave and the replacement will probably be hostile to us for repressing them in the first place. We shouldn't have artificially removed the previous regime, but after that happened, we should have helped them set up whatever form of government they wanted, then left. Artificially removing a government creates a vacuum and that's a bad thing- even though Sadaam was one of the worst thugs in human history.