Not surprising
To keep it this way we need to urgently reform the Iraqi police and military to take over the peace keeping. There is certainly nothing reminiscient of VN or even Afghanistan in this operation.
Our military is effective because they are well trained at war. When it comes to policing the peace they are not nearly as effective. Picture the Marines being sent into Watts to put down the riot.
If we are going to be stuck with being the world's policemen we need to train some police divisions or learn to get into the background quicker.