There is another…theory, that Iran will persist in its drive to achieve a bomb—or at least a break-out capacity to get one quickly if it so desired. The Iranians say they never trusted Mr Obama’s offer of detente early in his presidency because of the heavier sanctions and the campaigns of sabotage and assassination that accompanied the offer. In the same vein,they deplore the American administration’s recent decision to drop its longstanding classification of the exiled People’s Mujahedeen of Iran as a terrorist organisation.

So Iran’s rulers will not easily trust future pledges to lift sanctions in return for nuclear concessions. In any event, Iran’s leaders may now believe that such concessions would destroy the Islamic Republic’s credibility and open it to a recurrence of the unrest that followed Mr Ahmadinejad’s disputed re-election in 2009. So it is possible that an American policy of containment, even an undeclared one, might lead to a long campaign of attrition of the kind that impoverished Iraq in the 1990s, while leaving its leader in power.

Anticipating trouble, Iran’s hardliners have been stifling the remaining repositories of dissent as fiercely as ever. The most notable of these is Akbar Hashemi Rafsanjani, an establishment heavyweight and former president who became an opposition figurehead after the contentious poll of 2009. The two most controversial of his five children—his daughter Faezeh and his son Mehdi—have recently been arrested, undoubtedly with the approval of Iran’s supreme leader, Ali Khamenei. Mr Rafsanjani had been expected to put up a fight when Mr Khamenei tries, as he probably will, to install his own nominee as president in elections that are due next spring. But with his children behind bars, the former president may favour circumspection over principle.

Excerpt, Iran: Behind the rants, uncertainty grows, Economist, Sept. 29,2012, at 54