Funny, the people that cry with outrage when Mexican Police cross the border by mistake think that it is OK to send search and destroy teams into a sovereign country.
Right, because the Mexican Police must pursue those dangerous terrorists who are plotting to blow up every donkey show between TJ and Rosario...
As for Pakistan, they're stuck between a rock and a hard place. The govt agrees with our position and wants to help, but a significant portion of the population is fully willing to rise to armed revolt at the drop of a hat if they think the govt is disrespecting Islam by cooperating with the U.S. Turkey has the same problem, except in Turkey the military has been the secular stabilizing force that steps in and smooths things out when radical religious groups get too powerful in the government. The Pakistani military is probably quite willing to step in and quell internal problems either in the populace or in the govt, but they are probably not willing to be a causal factor in any new internal fighting by cooperating with US attacks on Pakistani soil against either Pakistanis, or people who have been given safe harbor by Pakistanis. The Army can intervene during internal People vs. Govt. problems, but they sure as heck don't want to be forced to kill Pakistanis in order to save or foster cooperation with the US.
They have a tough problem, and if we push too hard we could potentially cause their govt to fall and be replaced by a radical islamist regime. That would undermine everything we've done in the region.