My own arm-chair general view - US should have never got involved in "nation building" in Afghanistan. It can not be done, and this will be proven in spades before too long.
Should have had minimal footprint, few boots on the ground, stay just over the border. Become another "tribe" in the conflict, albeit one with F-15's, drones and hellfire missiles to allow us to go after Al Qaeda when needed, and broker for their own conflicts.
My feeling is that if we got involved in “nation building,” we should have stuck it out. The decent people in these countries (Iraq and Afghanistan) were happy to see us and obviously thought that they were going to have a stable, secular society as a result. But the first thing we did in both cases was kowtow to Islam (their ideology), which was exactly their problem in the first place, and then the second thing was to announce that we were leaving ASAP.
If we’d done the same after we occupied Germany, Hitler (or his successor) would probably now be running the world.
I suspect/believe that there was much more to our involvement in Afghanistan than Al Qaeda. That the USA has over 100 ‘status of forces agreements’ with other nations is really a show of how extensive the USA’s involvement in the world is. This Nation has become so mired down in world problems that our own people are paying an exorbitant cost. I realize the world is not a 17 centuries one, but the Founding Fathers ideas for foreign entanglements should still have some guidance.