Iran will have lots to think about before attacking Israel.

For one thing they cannot launch a massive attack without also wiping out the Palestinians and a good chunk of Jordan from fallout as the winds go from west to east. They would need to hit Jerusalem and hard to imagine any Muslim doing that.

They would also need to hit the Israeli missile sites and Diamona which are also close to Gaza and the W Bank.

More likely they would just go for the major population centers on the coast but Israel with its 200+ warheads in the Megaton range, advanced missiles, and subs could easily launch a massive counterattack and still have plenty of reserves.

Also any Iranian attack would have to get through Israels missile defense system so they would need to use up lots of missiles and precious warheads. Israel doesnt need to worry about any of that when they counter attack.

A limited attack would not likely ‘wipe out’ Israel because of its better civil defense, hospitals, and high tech economy, not to mention being buddies with the US and American Jews who would pour massive effort into recovery. Iran on the other hand would cease to exist.

There is no way we should let Iran get nuclear weapons but they are really draining their resources and political capitol to get something they probably cant use. They would be much better off with an upgraded conventional military.