You can go to war and kill men however killing a man hardens his brothers' ideology.
Ideology is not an army, it's hard to fight. Radicalized Muslims will flock to Afghanistan, either to live under sharia laws or to be in a safe haven for Jihad training.
I suspect Afghanistan will head closer to life in the middle ages as it's gov't will neither be capable of governing, nor will they have international support, aid or investment. Life will get reduced to day to day survival.
I don’t think it’s going to be a safe haven…I do think it will be a drone strike training ground.