His chuminess with Saudi Arabia could be the trigger.
An added dimension is the whole "nuke" thing. Here's a recent article from foreignpolicy.com
How Close Is Iran to a Nuclear Bomb, Really?
Experts say Tehran has the capability to build a nuclear weapon within a few years but perhaps not the intent.
Iran confirmed on Monday that it has breached the limit on its stockpile of enriched uranium set by the 2015 nuclear deal, renewing concerns that Tehran could, within months, have enough weapons-grade uranium to build a nuclear bomb.
But experts say the violation is more of a symbolic move than a concrete step toward obtaining a nuclear weapon. Though most agree that Iran has the expertise and capability to eventually build such a device, it is not clear that Tehran has the intent or even sees the necessity of doing so.