American officials say they will pursue hostile gunmen into Pakistan. This right of "hot pursuit" is being contested by Pakistani government officials. So far, the US has employed hot pursuit a few times without incident. The Afghan border area of Pakistan is sparsely populated, and most of the locals belong to a Pushtun tribe. American Special Forces and CIA have been working with these tribes for over a year. Some tribes have become friendlier than others, but at the moment the Pakistani government does not have an enormous edge in the influence department when it comes to these tribes..