One thing to keep in mind about the surge in Iraq is that when we surged into Baghdad and chased the fleeing al Qaeda types into the Baghdad belts, the enemy did not flee to Anbar province.
Which is strange considering they declared it the site of their future proto-caliphate. And it is closer to their supply of jihadi suicide bombers running through Damascus. You'd think al Qaeda would have run that way.
But due to the change of heart of the Anbar Sunni Arabs, there was apparently no traction within the province for al Qaeda. The jihadis fled to areas considered less dangerous to them than Anbar.
Consider this a dog that did not bark.