What is going on in Pakistan?

Check out this BBC report:

Nato forces in eastern Afghanistan say their helicopters have been fired upon by a Pakistani military checkpoint. The Western alliance said its aircraft had not crossed into Pakistani airspace when they came under fire over Khost province, news agency AP reports. The incident comes amid growing tension over a number of recent incidents at the Pakistan-Afghan border. Earlier this week, Pakistani troops fired warning shots at US helicopters near the border, local officials said. And on Wednesday, a drone believed to be operated by the CIA crashed inside Pakistan. (...) There has been tension between the two countries since 3 September when the US conducted its first ground assault in Pakistani territory on what it said was a militant target in South Waziristan. Pakistan reacted angrily to the action, saying 20 innocent villagers had been killed by US troops. Local officials have said that on two occasions since then Pakistani troops or tribesmen have opened fire to stop US forces crossing the border. The claims have not been officially confirmed.

Amazing, no? It appears that NATO and Pakistani forces are routinely sniping at each other, or, at least, the Pakistanis are shooting at Americans. Clearly, these are very minor skirmishes, but such small skirmishes have a great potential to rapidly get out of hand. The most likely scenario is and air-to-air engagement between NATO and Pakistani aircraft along the border (as had happened during the Soviet occupation of Afghanistan). And Pakistan is supposed to be an *ally* of the US in the GWOT...

If this kind of things continue, and there is no reason to suspect it will, or if the escalates, as it might, we might see a fundamental qualitative shift in the entire US operation in the Middle-East from (allegedly) fighting a terrorist group to a military conflict with a major military power equipped with nuclear weapons.

In the meantime, al-Qaeda is blowing up hotels from were US Marines seem to be conducting covert operations in Pakistan.

Is the Empire uniting everyone in Pakistan in a common anti-US front?