Is nuclear fallout serious enough for you?
Get real will you. Israel has no need to nor the inclination to nuke Iran. People throw around the nuke word too loosely. There may be a few rabid dogs in every nation but there are still more sane and educated diplomats.
Put it this way, if there were ANY leader crazy in any nation insane enough to seriously consider nuking another country, especially one nearby, their internal security agency would take all necessary actions to neutralize that leader. They might even ask for external assistance.
The only nations you need to really worry about under such circumstances are precisely the leaders such as Iran that the West is trying to prevent from having a nuke. The reason being is just like a few other nations, the chances of their internal services confronting and preventing their leader from acting is far lower.
This is the difference between democracies and dictatorships, there are checks and balances.