Dunnigan mentions it, but doesn't want to draw the conclusion. Sunnis have good reasons why they are waging an insurgency and these reasons won't go away - unless the US and the Iraqui Council come up with a political solution that is seen by them as legitimate and fair. It might be true that there were few successful insurgencies since 1945, but it's also true that resistance movements which are based on an ethnic group are the hardest to extinguish.
