From what i can remember, my father told me that south korean units in the viet nam conflict were very effective at keeping the areas assigned to them pacified and under control. One reason they were so effective was they didn't split hairs about the difference between particpants, such as the viet cong and the locals: if you were in the wrong place, at the wrong time, well you could very well become grave fill. If they were there to do a job, such as keep the people out of the area, well they applied that rule to everyone.
I think the iraqis are in for a bad shock if the same modes operandi applies to them as well. They simply arent going to screw around with those people.