Israel cannot do anything. It will get crushed a week into a war and beg NATO to intervene. It all depends on if US will fight a war on the Jewish Supremacist Colony's behalf. Otherwise Israel has to swallow the blow there is nothing they can do. We are probably underestimating Iran's missile defenses(maybe). But even without, it will crush Israel.
Israel lacks economy and logistical capability to fight a war with Iran. Even a short term one. It needed US massive funding and supply routes to be activated to do what it did in Gaza. It requested US to take on Hezbollah if Lebanese front was open.