Baghdad isn’t Saigon.
It’s a good 350miles inland.
Even with a battalion off the coast, you’re only talking about 15 minutes of ground power before they run out of ammo.
Provided an adversary lacks the ability to perform a coordinated attack or they are less than about 2000 in number, it isn’t a pretty situation.
The only evacuation possible with the numbers given in the press, is a peaceful evacuation.
The question is how many people can fit in a helicopter, how long does it take round-trip, and how many people are on the ground waiting to be rescued.