The simplest measure of Iran’s strength is its currency. When Barack Obama became president, you could buy 9,700 rials with one dollar. Since then, the dollar has appreciated 60 percent against the rial, meaning you can buy 15,600 rials. Iranian President Mahmoud Ahmadinejad told parliament recently that the latest sanctions were “the most extensive . . . sanctions ever” and that “this is the heaviest economic onslaught on a nation in history . . . every day, all our banking and trade activities and our agreements are being monitored and blocked.” The price of food staples has soared 40 percent the past few months, Reuters reported this week…

These public disagreements are part of the Iranian political system’s disarray. Just two years ago, Ahmadinejad was allied with the nation’s supreme leader, Ayatollah Ali Khamenei. Now they are adversaries. The reformist bloc, including presidential candidate Mir Hossein Mousavi and former president Mohammad Khatami, is also opposed to Ahmadinejad. The clergy are divided and losing power. Above all of them sit the Revolutionary Guards, who are turning Iran’s theocracy into a quasi-military dictatorship. None of this suggests political stability or strength…

The Obama administration has put tremendous pressure on Iran on a variety of fronts — far more pressure than the Bush administration was ever able to muster. This is, in part, because the pressure has been brought to bear, wherever possible, with other countries. The United States does not buy oil from Iran. But European nations, Japan and South Korea do, and if they go along with a new round of sanctions, Iran faces the real prospect of an economic freefall.