The truth is that what the Pakistani government calls “violating sovereignty” is really just violating a border. It is clearly not in control of the tribal regions, which by definition means it is not sovereign there.

This puts the US in a pickle, especially if a 9/11-scale attack happens that was based from those tribal regions. Despite the lack of sovereignty, these areas play a part in domestic politics. This means if the US conducted a full-scale invasion, it would be trusting in the Pakistani army to quell any Islamic revolution that followed (among many other things).