We must learn how to fight in Afghanistan with the enemy having a safe sanctuary. We cannot get Pakistan to shut down the jihadi recruiting and training areas inside Pakistan. And we cannot just poke around on our own too much to avoid destabilizing Pakistan. Pakistan may be far from ideal the way it is, but the way it is now is also far better than it might be.
So we must kill them in Afghanistan in large numbers and make sure they don't stick around to learn the local areas. We have the edge in killing the enemy and knowing the area. So the enemy flees to Pakistan when winter approaches.
As long as this pressure means they must leave Afghanistan before winter sets in and then enter Afghanistan in the spring to fight again, interdicting the border with artillery fire bases will inflict more casualties by striking the enemy in motion twice a year and slow down supply efforts.
Killing the enemy inside Afghanistan and interdicting their entry and exit isn't as good as getting rid of the Pakistan sanctuary, but the situation is what the situation is.
I would hope we don't feel compelled to fight with this disadvantage in Iraq in regard to the Syrian and Iranian sanctuaries. Destabilizing those countries should be our goal and not an unfortunate side effect to be avoided.
But then, we've done nothing about them for three years now. Perhaps we need a general theory of fighting insurgencies with enemy sanctuaries completely off limits.