If Israel is hit and all moral obstacles are now diffused, because Israel tells the UN to shove it, then the Iranians will be massacred horribly. Once the Iranian blood is flowing by one of the world's most powerful militaries, they will probably wish to surrender and even try to oust their own leaders with hope of not being wiped out. Remember, the Persian people as a whole, may not like Jews, but to fight a war against a peaceful nation, that was no threat to them, just so some big ,fat psychotic mullah, who considers himself next in line to the Prophet MuhamMAD, can satifisy his bloodlust, no this will not happen. THe Persian people don't have such a beef with Israel and if their cities are all on fire and bodies laying all around because Ahmedinjab and Khamenei decided to bombard Israel with missles, I can forsee they will not have the popular support, since the morality of the people already is so against their leadership.
Their army is disorganized, outdated and they are taking away the food money of the people to fund whatever pathetic military they have. The only hope Iran has is that they get full support of Russian technology. That would essentially amount to a proxy war of Russia vs Israel and Russia would not be able to hide themselves ..
Israel will also destroy Iran's oil supply, leaving the country totally helpless and if Israel controls the flow of oil , they will have upper hand on Iran.. Remember, Israel survives through its brains, strong spirit and ingenuity.. Iranians surive and progress because they have oil.. Oil is just a material substance and can be destroyed if needed. No Oil.. No Islam.