When we changed tactics to a series of rebel like raids, that is when we began to fail.
We should either leave Afghanistan post haste, or else treat it like a real war, i.e. advance troops and material and decimate anyone or anything that gets in the way.
As the movie title goes: No Blade of Grass.
It was hard to win in Vietnam as long as the enemy had untouchable sanctuaries, and were being supplied by Russia and China.
The Islamics are being supplied and given sanctuaries in Pakistan and Iran. Remember where we finally found Osama? In Pakistan, in a safe house just up the road from their military academy?
We need to understand that Afghanistan is a distraction, a puppet show, and start thinking about how to deal with our actual enemies. But first, get our troops out of there.