Honestly what gets me about evac failures and abandonments is the Berlin Airlift.
We had the logistics to mount a months long rescue operation that could get everyone fleeing out decades before these rushed withdrawals.
Everyone in Saigon and Kabul could have been gotten out, fuck we could have mounted a rolling evac bringing collaborators behind lines and transporting them in a trickle so that the last folks out are in a relatively empty air schedule. Expanding and contracting sphere, keep everyone who’s in it willingly behind the line so long as they willingly continue to move with it.