So, let’s return to a familiar subject: The use of oil as a political tool in international relations.

Iran’s heading toward nukes. The U.S. wants to prevent it. So the U.S. is threatening economic sanctions — specifically, threatening to restrict Iran’s major export, oil.

But, ahem, don’t we need that oil? Points out Iranian President Mahmoud Ahmadinejad, "You need us more than we need you. All of you today need the Iranian nation."

Grist relies on the support of generous readers like you. Donate today to keep our climate news free.

Kevin Drum asks, and Stuart Staniford answers, the obvious question: Could cutting off, or even slowing down, Iranian oil exports really do that much damage to us, or to the world economy?

Grist thanks its sponsors. Become one.

The short answer is: Yes.

So the next time somebody’s calculating the economic cost of Kyoto, or a carbon tax, or emissions caps, I hope that in the “continuing the status quo” column they don’t forget to include, “inability to prevent a large Middle Eastern country headed by maniacs from acquiring nuclear weapons.” How much does that run these days?