We should have never been there at all.
But the US has been involved in the region for a long, long time. If you had a time machine you might well want to undo that, but you'd have to go back quite a long way, long before the presence of these specific troops.
Disentangling from something you've been entangled with for a long time, needs to be done very carefully, with preparation and thought. Britain failed to do that in India and the result wasn't pretty.