This is the most likely scenario (in my opinion):

No one will do anything until Iran obtains multiple nuclear weapons. Iran will give these to "terrorists" NOT aligned with a particular nation. These terrorists will successfully detonate several warheads simultaneously and the former country of Israel is destroyed. The land will be uninhabitable for thousands of years.

That's it.

A couple of minutes later the US will have a decision. Who did this and how do we retaliate and against whom?

The issue with nukes and the tiny country of Israel is that, unlike the US, their entire country can be destroyed by a handful of nukes in a matter of minutes. Once I wrap my head around that sobering concept, I find I'm a bit more sympathetic to their "concern". That does not mean I necessarily support participating in a pre-emptive war. It simply means I'm sympathetic to Israel's fear.

The path forward for Israel is murky and dangerous. I'm glad I don't live there.