Afghanistan pull out was always going to be a disaster

[Klaralven]

18. The problem is how do you "retract" an air bridge?

You can "extend" an air bridge by dropping paratroops to seize an airport. This works because you can choose a weakly defended airport and have the advantage of surprise. The defenders have the disadvantage of having to defend all the airports, while the attackers can concentrate forces on one.

However, once you have completed your operation, how do you evacuate the last personnel given that they are under attack? In this case the enemy can mass his forces against your last forces on the ground.

In the case of evacuating a beach, you can use naval bombardment and naval air power to cover the last units off the beach. They can't be totally protected, but the Navy can do a better job.

Afghanistan, being landlocked, was never going to end well.