John Cole explains blowback:
When you bomb people and kill their family, friends, and neighbors, burn down their homes and burn down their businesses and kill their livestock, spewing unexploded ordnance and munitions in fields where they work and their children play, it pisses them off. Many of them even get pissed off enough to fight back against the people they think are responsible for the bombing. They probably even form lifelong grudges when they find their mother and children in thousands of bloody pieces in their former homes.
In other news, NATO supply trucks are again struck in Pakistan.