Israel won't use nukes .. the real question will be if Iran has one or not
I don't think iran has one - and if they did, and got one off against israel - they would have to be:
- sure the warhead would work, not having tested it
- sure the missile would go to the right place
- sure israel wouldn't intercept it
and once they fire the thing (success or not), they are toast 15 minutes later.