It appears that the Pakistanis have gotten a bit hot under the collar about US incursions, as they have just authorized firing on US troops if they cross the border:

“The orders are clear,” Maj. Gen. Athar Abbas said in an interview. “In case it happens again in this form, that there is a very significant detection, which is very definite, no ambiguity, across the border, on ground or in the air: open fire.”

Jeff Stein of CQ politics, makes a very good point here, that Pakistan increasingly seems to resemble Cambodia before the Khmer Rouge.

• The Cambodians tolerated the North Vietnamese, the Pakistanis the Taliban.
• The US engaged in cross border bombing to target their opponent.
• The US escalated to cross border troop actions.
• The effect of the escalation was to drive the local populace to our opponents.
• The leader of the country was ousted.

There is one difference though, which Mr. Stein notes: Pakistan has nuclear weapons.