Afghanistan is a country with 41 million people on a land mass of 252 thousand square miles.
The US consists of 300 million people on a landmass of 3.1 million square miles.

The math is SO FUCKING BAD for the US government. The entire Taliban was really only around 20,000 fighters. Imagine TWO PERCENT of Americans are crazy enough to directly fight the US government, that's 6 million people. The US army is only 1.6 million people total.

There's literally no way for them to win, even in case of a SMALL civil war.