What would serious sanctions look like? To begin, the US, perhaps with the assistance of some European allies -- French President Nicolas Sarkozy, German Chancellor Angela Merkel and British Prime Minister Gordon Brown have all indicated support -- would cut off shipments of gasoline and other refined petroleum products to Iran.
Only a few companies, mostly European, now supply these products which Iran desperately needs because, though a major oil producer, it has constructed few oil refineries. Shipping companies, banks and insurance companies that underwrite the trade also could be discouraged from continuing to participate in this business. Legislation to achieve such results, for example, the Iran Refined Petroleum Sanctions Act, has strong bipartisan support -- three-quarters of both the Senate and the House.
James Woolsey, CIA director under President Clinton, has suggested that the White House and Congress, in addition, should make clear that from now on "any company that does any kind of business with an Iranian entity - not just the Revolutionary Guards, not just oil and gas companies, but any entity - can do no business with the United States government."
Time is of the essence: Iran's rulers already are conspiring with anti-American autocrats - in Russian, China, Venezuela and Turkmenistan, for example - to find ways to break such an embargo, should it be imposed.
There are those advising President Obama that such pressure can only serve to antagonize Iran's rulers - who, they insist, have legitimate grievances against us but really only crave respect and are eager for dialogue, compromise and cooperation. It requires forbearance -- given repeated Iranian nuclear cheating, the fraudulent elections and the brutal oppression of protestors, the empowerment of Hezbollah in Lebanon, the use of Iranian weapons and perhaps operatives to kill Americans in Iraq, Afghanistan and, before that, in Lebanon and Saudi Arabia, the Holocaust denial and the genocidal threats -- not to regard these advisors as terminally naïve.
Others argue that nothing short of military force can be effective, that Iran's rulers will withstand economic pressure, no matter how crippling, in order to get their hands on weapons of mass destruction they can use to intimidate - or incinerate -- those they see as enemies of God. They believe it is too late for sanctions to work.
But why not test that theory - and quickly given that Iran is now sprinting toward the finish line? If sanctions prove ineffective, at least we will know for certain that only two options remain. The first is bad: the use of force by the U.S. or, more likely, Israel. The second is worse: watching passively for the second time in less than a hundred years as fanatical and ruthless tyrants acquire the capabilities to match their clearly stated intentions.