* Korea: Stalemate, which is still a problem now 70
years later
* Vietnam: Loss
* Gulf War: Victory
* Afganistan: Loss, after 20 years of fighting
* Iraq: Mixed results after 8 years: Saddam Hussein threat
eliminated, Iran and ISIS made significant gains
Iran is larger and has more people and resources than Afghanistan and Iraq combined. Terrain in Iran is a game world-builder's fantasy of defensibility:https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2F...
Iran is far more capable militarily than Iraq and Afghanistan and, particulary, their military may be world's the leading experts on assymetric warfare; they train everyone else - Hezbollah, the Houthis, etc. Their proxies held off the US military and allies in Iraq, a neighboring country, where Iran had far less motivation than to defend their own homes from a US invasion.
The US could win given unlimited political will and time, but it would be very costly and anyway, the US couldn't sustain that will for much easier situations in the prior two wars. Nobody is crazy enough to launch a ground invasion of Iran, I hope.