In the 2000s, the American military held a massive joint exercise on the invasion of a mountainous middle eastern nation. (It was obviously Iran without saying Iran.) The exercise was supposed to be a demonstration of America’s military to show Iran that America really would wipe them out if a war ever happened, which looked inevitable at the time.

A very talented US General was chosen to lead the not-Iran side. He was given the resources that Iran was believed to have at the time. And through a series of very expertly timed and choreographed attacks he won. He crushed the US Navy. The whole exercise was a massive embarrassment for the military. The big media announcements were obviously all cancelled.

Granted, the General that was put in charge of not-Iran was extremely brilliant and had very detailed knowledge and experience of US capabilities and how to exploit vulnerabilities. But it’s still studied in the military schools as a case study in not underestimating your enemy.