I have a hypothesis that I've been mulling over for a while. Some info over at Captains Quarters
has reinforced this idea for me: when Iraq finally takes over for the USA, they will be effective. Now, this depends on three primary conditions, I think. They need to stabilize the country enough for commerce to flourish. They need to prevent conditions, such as in Iran or Saudi Arabia, wherein radical Islam can incubate and grow. And, similar to, but not the same as the last point, they need to crush radical "insurgents."
This last one is where I think they will be more effective than us. The "ethics" of that region are different from our ethics here at home, and this prevents us from taking certain measures that would be more effective than our current procedures. We wouldn't be able to get away with such things anyway, since they would be used by the radicals to show that we really are just as evil as they say we are, even though they are demonstrably worse even than that.
On the other hand, the Iraqi government, sans USA, could be, and should be, very brutal with the "insurgents." I doubt the insurgency would be as effective if the USA was not there, provided that the Iraqi authorities have the numbers and the loyalty in their ranks to be strong enough to deal with the problem. Then, through unfortunately severe but neccessary brutality, they could smash the insurgents.
Our hands are tied in this regard. We will never destroy the insurgency since we cannot and will not be as brutal as needed, and we would see diminishing returns for our brutality anyway. The Iraqis can be more effective. There, that's my beef.