A new 51st state?

I have been meaning to ask a question for a couple of days now. My understanding of international law is very limited, but I am pretty sure about this: one of the fundamental tenets is that when country A launches a military strike (soldiers, bombs, etc.) on the soil of country B, that attack constitutes an act of war. At any rate, that is sure how Fearless Leader has justified our War on Terrah in the aftermath of 9/11.

So why wasn't our January 13th aerial bombardment of Damadola, Pakistan which killed at least 18 Pakistani civilians, an act of war?

Here's the answer, from the Pakistan Daily Times, which claims to get it from Time:

Washington has an understanding with Islamabad that allows the US to strike within Pakistan’s border regions, providing the US has actionable intelligence and Pakistan cannot take firm action, according to a report in US weekly magazine Time.

The source of the report is a Peshawar-based Pakistani intelligence official. “Pakistan’s caveat (to the agreement) is that it would formally protest such strikes to deflect domestic criticism. Some ranking Pakistani officials deny such an agreement exists,” says the report headlined ‘Can Bin Laden be caught?’

This will not go down well with the man on the street in Pakistan. Pervez Musharraf was generally seen as far too cozy with the Great Satan even before we treated his country as another Vieques (only with people). So now that question #1 seems to have been answered, here's question #2: What did we promise Pakistan's weakening strongman to get him to make a mockery of his country's sovereignty?