The Obama team wants to pursue talks with Iran over its nuclear program, no matter who wins there. Fine. But the issue is not talk or no talk. The issue is leverage or no leverage. I love talking to people — especially in the Middle East — on one condition: that we have the leverage. As long as oil prices are high, Iran will have too much leverage and will be able to resist concessions on its nuclear program. With oil at $70 a barrel, our economic sanctions on Iran are an annoyance; at $25, they really hurt.

“People do not change when you tell them they should; they change when they tell themselves they must,” observed Michael Mandelbaum, the Johns Hopkins University foreign policy specialist. And nothing would tell Iran’s leaders that they must change more than collapsing oil prices.