Wow, man, I used to think you had liberal sensibilities... but you are going complete MAGA, aren't you?
(For the record, I attended parochial Catholic Schools in Chicago 45-55 years ago. My HS graduated no less than FOUR Chicago Mayors- the good ones, not the fools we've had in since the last one retired.)
Leaving aside your open Islamophobia (We'd be scewed if you think that 1.5 billion Muslims are as evil as you think they are), the Ayatollahs would have the same problem everyone else who ever got a nuke has had. Anyone they might want to use that nuke on either has nukes of their own or is allied to someone who does.
The real problem is this, and try to follow along.
Saddam gave up his nukes, and we killed him.
Qadaffi gave up his nukes, and we killed him.
Kim Jong Il (father of the current nut, Kim Jong Un) kept his nukes, and the world bent over backwards to appease him, even sending him food when communism didn't work in keeping people fed.
So it would seem the real incentive for the Ayatollahs is to keep building a nuke, because the West certainly can't be trusted to keep their agreements or stand up to the Zionists even when they commit genocide.