Check out a contour map of Iran. It is tough to turn a mountain ito a parking lot. Even nukes are linear and can't bend around maountain valleys. Sadam made the mistake of trying to takeout Iran. Even with the financial backing of the USA and Saudi Arabia and the use of chemical weapons, Iraqi forces got turfed out of the low lying floodplains after the Iranians regrouped in the mountains and came screaming back for revenge. I am no trying to be pro-Iranian; just stating the facts.
Not dealing with the facts is exactly how we got into this mess. Don't take a knife to gun fight.