Which advisor told him that the Afghan Army, after 19 years and billions in advance weaponry and armament would devolve away during our withdrawal? After the Afghan Army folded, that's exactly what they did, they added more personal. How many have we gotten out since the Afghan Army, that we paid for with blood and treasure, quit the field?
The reality is, it is the policy of Nation Building (bipartian) that has failed miserably. By blaming the end result on someone, those and those like minded individuals who choose the invasion, occupation and Nation Building route in foreign lands are bound to try it again.