How would "America Destroy Iran"?
The first use of nuclear weapons is a war crime. There would be a drift of the fallout that would poison the world. Remember those Cumbrian sheep after Chernobyl?
The Iranians endured over nine years of war against a US-backed Iraq in the 80s. They have the protected infrastructure as a legacy of that.
Bibi could start a war with Iran to save his own arse.
The evacuation of Baghdad would make Saigon 75 look like a picnic.