How would you like a foreign power invading and running your country? You better believe a large part of the Taliban are fighting not out of religious conviction but essentially (Pashtun) nationalism.
US did it during WW2, and it seemed to work out fine.
Only thing is that when they left, we made sure the Nazi's didn't come back.
Right now they were training Afghans to have their own military, but it's all so corrupt that it is just an impossible task. Those who can will flee the country instead of fighting for it.
The many that collaborated with the US forces in any way fear retaliations. And if history provide insight, heads might roll. Look at what happened with French woman that slept with germans after WW2. Life is harsh and injust by default.
Only thing is that when they left, we made sure the Nazi's didn't come back.
Right now they were training Afghans to have their own military, but it's all so corrupt that it is just an impossible task. Those who can will flee the country instead of fighting for it.