Plenty of precedents
The US in Iraq is much like the Roman legions in many far outposts whose technology was advanced and whose fighting methods were vastly more complex. They were hated too, but feared. Just like the US. The Romans, were occupying lots of unstable areas where they were the law and order, besides being occupiers.
And like the Roman legions, it was corruption, decadence and squatters back at home that destroyed the morale and sustainability of the troops and outposts. The public will to sustain them, refresh them and supply them evaporated.
Pelosi would make a great corrupt Roman senator looking out for their own interests against that of the empire.
;-)