bridge blown in the khyber pass

This is what happens when you squeeze the ballon:

Hidayatullah Khan, a government official in the region, was quoted by Reuters as saying that the 30-yard-long iron bridge was located 15 miles northwest of Peshawar, the capital of the restive North-West Frontier Province.

Pakistani officials said they were assessing the damage and teams had been sent to repair the bridge. But it was not immediately clear how soon the trucks carrying crucial supplies for NATO forces would be able to travel through the Khyber Pass to Afghanistan.

More than 80 percent of the supplies for American and coalition forces in Afghanistan flow through Pakistan. Attacks aimed at choking the supply lines have become increasingly frequent and brazen, *despite the presence of Pakistani security forces in the area.

Or as commenter Soldiernolongeriniraq puts it over at Abu Muqawama:

Or, BECAUSE of the presence of Pakistani security forces in the area.