When basically everyone thinks that this war can´t be "won" by military means then there might be some truth to it. I´m convinced that the average afghan only wants to be left alone and doesn´t give a crap about the west or other powers as long as they stay out of his life - which if you know the afghan history basically never happened. You´d propably all do the same and defend what you consider your home.
One more thing where i think you both, Slick and Pud, are not understanding the situation completely is that like i said earlier Afghanistan is not your typical country with people feeling as a nation and that is why you won´t "teach" them to not attack the US again. Al Qaida - a non state actor - attacked the US. They were backed by the taliban - a non state acteur - which were not a government, they were victorious non state actors who beat the Mujaheddin in a civil war. But even they only had control in certain - albeit big - parts of the country. Because Afghanistan is hardly a state in the western sense and the taliban were not a gouvernment in the western sense bombing the country to shit (which it already was after 23 years of war btw) would not have changed anything except immediately bring the taliban back into power stronger and with more support than ever after the airstrikes stopped. Btw Slick, Pakistan would and did still support the Taliban, the region in the south west is nearly as much out of control as on the other side of the border. The pakistani government does not have a real influence there.
You know what i think would have been the right thing to do? Work closely with Pakistan (and other regional acteurs) and get them to stop supporting the opposing afghan infrastructure and only use airstrikes/drones and special forces on a small scale to get the leaders of AQ and the taliban. Forget bombing the crap out of that country, avoid attacking the normal afghans and thus creating more enemies and hate towards the west in that region and don´t put a big number of troops on the ground which for the people feels like an occupation.
While doing that support the afghan civil society (starting in Kabul, this takes time) and groups which advocate personal freedom, educate talented people in the west where they work towards a more liberal lifestyle in their home country. Work on a political scale with the relevant acteurs. This doesn´t all need to be done by the state. NGOs can do a lot of that using development aid. Take time. A generation or two are likely before the effects sink in deeper
