"A nuclear war is about to erupt and our public is practically unaware of it."
You're right that public on awareness at that point is ridiculous. But I would change your statement to say that a nuclear war may erupt. For one thing, a successful preemptive Israeli strike would not be a "nuclear war" if it did not use nuclear weapons. It is possible that the Israelis could succeed with a non-nuclear strike.
I'm not so sure it would be effective enough.
Israel can mount a strong fighter strike against Iran, including aerial tankers. But they would need to cross either Turkey (unlikely), Syria (unlikely), or Jordan and Iraq (most probable). Quite possibly, Jordan would permit it. We need to approve it also as we control Iraqi airspace. However, this would put us in full collusion with an Israeli strike. Now, Israel might be able to mount a multi-aircraft strike, but it would probably of necessity be a onetime event and might cripple, but would certainly not destroy Iran's capability or production. It would also mean full war. A one-mission decapitation would probably be possible only with nuclear weapons. Iran has just too many hardened targets to do it effectively with a single mission package.
The alternative is - as long as we're in for a dime, in for a dollar - we may as well be the ones to do the air strikes, including warship and submarine assets. We can bring much more force to bear and have local assets. Israel should stay out of it for political reasons. A massive first strike and a series of followup strikes are probably the only thing that would do the job. Then, we would have to face the Iranian Army and defeat the entire country because there is no turning back.
Again, this would mean open and preemptive war with Iran, but that would be far preferable to nuclear weapons detonated over our country which is a very possible outcome if nothing is done and done quickly.
However, in today's domestic political climate I am dubious we will do anything in a preemptive way. We are simply too politically unfocused on the threat to be able to meet it head-on with a massive military campaign.