Oh dear. Drivers in Pakistan are refusing to transport supplies across the Northwest Frontier to NATO and US troops in Afghanistan. 75% of US and NATO supplies go that way. Which means they're either going to have to drive their own damn trucks, find a new supply route in a hurry, or learn to fight a war without food, fuel, ammunition and toilet paper.
This is a major setback for the US, and unless they resolve it quickly, it's all over for them. Modern armies - particularly the US army, with its dependence on helicopters - are hungry and thirsty beasts. Cut off their supplies, and they wither and die.