Iran hasn't threatened to destroy, they have made it their stated mission to "annihilate" Israel. I doubt Israel would have any ill-will towards Iran if Iran didn't first say that about Israel.
Israel and Iran were BFFs right until the revolution and Israel has hundreds of thousands of Persian jews. I'm sure relations will be very quickly amended if the current regime falls.
Iran hasn't threatened to destroy, they have made it their stated mission to "annihilate" Israel. I doubt Israel would have any ill-will towards Iran if Iran didn't first say that about Israel.