The short answer should be - back off.
An attack on Iran would almost certainly lead to a wider regional and then global conflict. Muslims throughout the Middle East are not just going to sit around and do nothing until it is their turn to be attacked by the West. They will act and those that live in countries with pro-western regimes will rise up and depose their own governments first.
Think about what happened in Iraq - the West won the war and then lost the peace - with more troops being killed after the war had supposedly been won.
Now take that scenario and scale it up so that it encompasses the populations of all the Arab nations. The manpower required to occupy and subjugate such a mass of people will be enormous. The West would have to stay on a war footing: with martial law in place and domestic populations virtually enslaved to serve the war machine, for generations to come - or until the oil runs out.
The consequences of such an attack are unthinkable - many millions will die as a result of this war should it happen.
What price then a litre of petrol?