I'm just hoping Iran uses their nearly-completed nukes against France, personally. Not that I have anything against them, but it would be pretty funny for the French military to get wiped out once again in history.

In all seriousness, yeah, it wouldn't take a lot to see some sort of super-spike to $10-15/gallon in a major global crisis, but it wouldn't last very long in the grand scheme of things. It would likely take only one to two decades to start plowing over the vast usable croplands the US has in a sustainable way to produce enough biofuels, along with migration towards vastly more fuel efficient mass transit and personal transportation. Telecommuting will also likely become mandatory for nearly all jobs where it's possible, and even jobs where it isn't possible, we'll see more of the 4x10 workweek or 3x12 / 4x12 workweeks to cut down on commuting.

This is a great nation, but an immensely stubborn one, to be honest. I can easily envision how it really could take two decades to get us back to something like $4-5 transportation fuels (like ethanol and biodiesel) but it wouldn't be the end of the world by any means. 1929 - 1945 was a pretty dark period, economically speaking, and we pulled out of that OK too. I think we could survive a global collapse of the old oil economy model, it would just be hard, much like the great depression was hard.