This was not the American army's fault, they actually where able to drive back the Taliban and their allies, the failure is that we stayed there even tough it was clear the government we propped up there was selfish and corrupt. Bulk of the Blame goes to Bush and his generals.

I don't really think a harsher approach would've helped. The Soviets were much harder on the Taliban than the Americans were, with their scorched Earth tactics, and the outcome was still the same.