Way beyond any "success" claimed by Petraeus, what's happening in Anbar is once again a replay of what happened in eastern Afghanistan in 2001. Local tribes profit from US largesse - and weapons - and then proceed with their own tribal and/or nationalist agenda. What matters for all these players, most of all, is restoration of Sunni power. The Dulaimi tribe and sub-clans, armed by the Americans, as soon as they have a chance, will try to topple the US-sponsored puppet government in Baghdad.
Behind the Anbar myth