The LA Times has a piece on the General Petraeus and the "surge," which quotes Ken Pollack thus:

"We are doing it, and all the other smart aspects of the new Baghdad security plan, very late in the day," said counterinsurgency expert Kenneth M. Pollack, a former National Security Council official now at the Brookings Institution who was an advocate of the 2003 invasion. "It is going to be very difficult to build up the trust among the Iraqi public to make any of this succeed. ...If we're not willing to stay for the months, if not years, it will take to regain the trust of average Iraqis, none of Petraeus' smart moves are going to work."