Pakistan is trying to mend faces with local Islamic radicals in the face of al Qaeda calling for the overthrow of the Pakistani government. Al Qaeda is understandably upset because Pakistan has arrested, and turned over to the US, some 500 real or suspected al Qaeda members in the last two years. And recently, army troops and police have started moving into tribal areas that have never been entered that way in the past. Al Qaeda had considered the tribal areas a sanctuary. However, the Pakistani move does not cover all the tribal areas, but does make it more likely that government forces would enter a tribal area where American and Pakistani intelligence believes key al Qaeda members (like Osama bin Laden) are hiding. Pakistan has also been allowing numerous Americans in civilian clothes to operate with Pakistani troops in tribal areas. These Americans have been seen regularly by tribesmen and are probably CIA, FBI or Special Forces (who will often wear civilian clothes when working for the CIA.)
The US has agreed to provide spare parts and upgrades for Pakistanis two decade old F-16 fighters.