Well after 78% of Jewish voter went for the magic mussie what do they expect? Sorry Israel this is one conservative that say you are on you own now.
When you consider that the only person with the guts to take on Iran since 1979 was Saddam Hussein, then I'd say these fears are not without merit.
My prediction, for what it's worth, is that Iran will indeed get the bomb(s), but will hold them in reserve. Just in case.
They fear it rightly.