The WAY in which the US pulled out of Afghanistan was a monumental clusterf#ck.
OK so why do i think the US lead withdrawal from Afghanistan was a monumental clusterf#ck. There are many reasons which include, but are not limited to, the following:
1. Negotiating with the Taliban a hard, unconditional withdrawal date.
This agreement was a huge win for the Taliban and gave them a sense of certainty. The US had agreed not to engage any Taliban forces except in self defence whilst guaranteeing a date by which they would be gone. The Taliban could now engage government troops in the knowledge that they would not be directly supported by US forces, and in the knowledge that said government forces would be left completely on their own in a few months time. This really strengthened the fighting resolve of the Taliban whilst destroying the resolve of Afghan forces. If the US was determined to withdrawal her forces in 2021 then the withdrawal should have been conditional, with an aspirational withdrawal date that was subject to specific conditions. Indeed all stages of the withdrawal should have been subject to specific conditions being met. The US should also not have agreed to take no military action against Taliban forces except in self defence.
2. Withdrawing during the fighting season.
The fighting season in Afghanistan generally runs from April to October. Biden announced that the US would be withdrawing during the middle of the fighting season. The stupidity of this timing is hard to comprehend. It was like the US were seeking to do all they could to ensure that the Taliban would succeed.
3. Withdrawing the military before civilians and equipment.
The military provide security. In order to safely and efficiently evacuate civilians (both US citizens and Afghan allies) the US needed to control the area of departure, as well as the area from where most civilians were coming (eg the 'green' zone in Kabul). They also needed to keep open a secure corridor btw those needing to be evacuated and the evacuation point. The US did none of these things. The result was that some 200 US citizens were left behind along with many more Afghans who had helped the US over the years. This should be unforgivable. The US also left behind some 10 billion dollars worth of equipment. This included crypto technology as well as ECMs, used to detect improvised explosive devices etc etc etc
4. Failure to secure the external perimeter of Kabul Airport.
The fall of Kabul meant that the US were unable to secure the external perimeter of their only sizable evacuation point. Instead the US were forced to rely on the Taliban to secure the airport's outer perimeter. The result was that US and allied troops stationed on the airport's perimeter had their safety placed into the hands of people they had been fighting for the past 20 years. The Taliban were unable to provide the security required and 13 US servicemen lost their lives as a result. Their deaths are a direct result of the mind blowing stupidity and incompetence of those at the top whose decisions placed these troops in such a vulnerable position.
5. Giving up Bagram Air Base
There were only two airfields in Afghanistan capable of playing any significant role in evacuating men, equipment and civilians. One of these was at Bagram. In giving up Bagram the US left itself with only one location from which to carry out it's withdrawal. Voluntarily reducing your options is rarely a smart move.
And so the list goes on. All of the above mistakes were avoidable and their consequences entirely predictable. This is not a case of being smart in hindsight. The withdrawal however was driven by political considerations with no concern for the human cost involved.