Afghanistan was a quagmire.
1) The British and Russians learned that you cannot conquer Afghanistan,
2) that we were not prepared for General Winter, and
3) if we had any chance of success we would need forces on par with Desert Storm, or greater.
Hmmmmmm. We went in with only a fraction of the force, we used new tactics mixing sophisticated weapons with warriors on horseback and we formed an alliance and didn't try to conquer.