Russia has an interest in staying alive.
China has an interest in keeping it’s communist framework and enough workers alive to continue on.
Iran is looking for a way to get some asshole out of a well and they’ll do whatever it takes.
By instigating a confrontation that will assuredly result in the annihilation of their country and way of life, with a very good chance of starting a world war in the process?
As mad as the Mullahs are, I don’t believe they’re that stupid, but one can never discount that possibility.
The odds are still on the side of sanity at this time, IMO.