WE can't afford a war with Iran. It's not that they're too strong for us -- we could sterlize the whole country in an hour if we wanted to. Or we could carry out a nuclear counterforce strike and eliminate Iran's government, armed forces, infrastructure, and resource base. Oh, it could be done! But if we were to do that the entire world would turn against us. We would become the new Nazis.
Instead, here is what is going to have to happen: we are going to have to let President Nutjob get in the first shot. The Israelis are going to have to take one for the team. Only after an Iranian nuclear first strike on Israel, with the accompanying television footage from Hell, will the milktoasts and Machiavellis finally see the light. Only by the deaths of a couple of hundred thousand Jews will the world finally see Iran -- and Islam -- for what it really is.
Even then, I'm not so sure they would. We may have to go it alone no matter what. If so, we will face a global economic embargo at the very least. We will be rid of the Iranian nuclear threat, but we will become a pariah state.
This is the main reason I'm for a form of autarky. Sure, autarky is bad from an economic point of view. But a nation that is dependent upon the goodwill of other nations for the resources it needs to survive is not a sovereign nation at all. We Americans would definitely take a standard-of-living hit if we as a nation organized our economy on an autarkic basis -- but we would also be free to do whatever was necessary in situations such as this.
As it is, a whole lot of innocent people -- on both sides -- are going to have to die in order for the world to be rid of the human vermin that threaten us all.
Iran will attack Israel. Israeli forces will get most of the attackers, but one or two will get through. It may be Tel Aviv, Haifa, or Dimona that gets the nuke (I don't think the Iranians would nuke Jerusalem), but the end result will be horror no matter what. Only then will we, the Israelis, and perhaps the UK respond.
Or perhaps a merciful God will spare us all. Let us pray for that miracle.
The problem is not world opinion as such, but that the American people need to be prepared for the consequences of an unprovoked attack on Iran. The President would need to start the process of educating Americans that Iran is a threat to our survival. This would be impossible at this time given the almost total lack of support (and outright hatred) for Bush among the elites. Bush does not have Reagan's ability to speak directly to the American people over the heads of these elites (unfortunately). Therefore, as you indicate, some horrendous event will be needed to do the job of educating.