Iran, in exchange, reaffirmed that it would not develop nuclear weapons and agreed to leave its nuclear program exactly as it stands -- meaning with its nuclear installations and centrifuges to enrich uranium safely under Pickaxe Mountain.

The last four months were the exhaustion of a method rather than a failure of nerve. The Trump method flattered the adversary, let him believe he had won, dragged him to the table under threat of force, changed course without warning and staged unpredictability as strategy. All that might work remarkably well in the West, where leaders answer to electorates, markets and quarterly reports. It presupposes, however, an interlocutor who counts costs the way Washington counts costs.

The Islamic Republic counts by another arithmetic....

A power such as the US that cries wolf on Tuesday and extends the deadline on Thursday teaches a system such as Iran's exactly one lesson: that the wolf does not exist. Iran's rulers read the American desire for a deal, especially before a midterm election, as weakness, which by that arithmetic it was. Trump, who kept repeating that he wanted a deal -- in that way raising the price for one -- seemed genuinely trying to test ways not to destroy more of Iran. Last week, he gave up on that.

After Khamenei, nothing has changed in Iran, where the doctrine, the gallows and the wager on Western fatigue are those of February. What finally changed, last week, is Washington.

The snag in Iran is that those who wish to make a deal dare not do so because they lack a popular street base within the Khomeinist movement.

And those who can make a deal because they have such a base won't do so because if they do, they risk losing not only that support but also the wealth and position they have illegally acquired.

Beyond the stretchable 60-day "hostile truce," what is needed is a Plan B for Iran that takes into account the realities on the ground and the opportunity for positive change.