They started this mess never intending to win it because winning it meant going after Pakistan that created the Taliban in the first place.
Pakistan never dealt with militarily it has nukes and is friends with China.
Then the post 9/11 Bush-Cheney-Obama-Biden policy with Al Qaeda was to kill the leaders like bin Laden and recruit the followers to fight in Libya and Syria.
Some of those Syrian recruits morphed into Islamic State which is now said to pose a threat in Afghanistan.
I agree completely. Bush said we were going to treat everyone who supported the terrorists like they are terrorists. I knew we would never do that......