In my opinion the real problem for Iran lies in the north, on the border with Azerbaijan.
The Israeli-supplied Azeri military has already demonstrated its effectiveness when it curb stomped the unprepared and internally betrayed Armenian military and militias. Baku will eventually decide to intervene in the northern territories. If I had to guess, a "special military operation" into northern Iran is the most likely follow-up scenario goaded into and supplied of course by Israel/US. The goal will be to foment a civil war and begin the dismemberment process of Iran.
A little personal conspiracy theory I have is that after the last Israel/US intervention (when they mysteriously liquidated the only high-ranking and influential internal opposition of the Khamenei clan left) is that some sort of deal was worked out behind the scenes with the clan to get rid of the wizard-in-chief kinda like how Maduro was sold out. It is much easier to go to war with a country when it responds with only symbolic attacks and secretly promises to fight with one hand behind its back - provided cash and security flows for those at the top of course.