There was the Vietnam war for the US and the first Lebanon occupation by Israel.
Common problem: guerilla wars. Lessons not learned.

The most powerful army in the world can't stop it because of the nature of guerilla wars: those wars don't involve 2 armies in front of each other, one advancing , the other retreating.
If an army uses conventional means (bombs) to remove the enemy, it's going to hurt civilians and those civilians will very likely turn against the army no matter what its intentions were. (Parallels between Iraq and Lebanon abound).
Guerilla wars mean snipers, very small groups (able to run away, reorganize themselves, avoid communications, mix with the population) in towns which they know much better than the occupants.
It can go on forever. They're not cheating, they're only rewriting the rules of engagment to their own advantage. And they don't need nuclear weapons to terrorize.