A thaw in diplomatic relations with Iran is a silver lining

For all the optimism justifiably unleashed by the election of the moderate Hassan Rouhani – almost exactly a year ago – Iran has yet to lose its political fangs. The Shia nation led by Ayatollah Ali Khamenei continues to funnel arms and money to the murderous regime of Bashar al-Assad. Executions are frighteningly common.

Behind the scenes, a powerful deep state of intelligence and security services - a legacy of the 1980s Iran-Iraq war - opposes the kind of reform that would lessen its influence.

And yet there can be no question that under Rouhani there has been an “opening of the fist”. David Cameron said yesterday he would have supported improved relations with Iran in any case, but the mounting threat from Isis across the border in Iraq has added urgency to a rapprochement – and explains the decision to reopen Britain’s embassy in Tehran.

Circumstances have changed dramatically since the embassy was mobbed in 2011 and UK diplomats pulled out of the country. The President’s record on human rights is, admittedly, poor. Promises on press freedom and the rule of law remain unfulfilled.

Yet two factors ought to curb some of the criticism; first, Iran’s political set-up is labyrinthine, and, though the Twitter-friendly Rouhani was levered in to power by young, liberal voters, he has long been a close friend of Khamenei - never quite the no-holds-barred ‘reformist’ of Western caricature. Second, much of the President’s attention has focused on the nuclear issue.

His primary mandate is to extricate Iran from the straitjacket of multilateral economic sanctions that, since early 2012, has heaped misery on the Iranian people. An interim deal to limit uranium enrichment, reached in January, lifted around $7 billion worth of sanctions. The release of clamps on far more – including those on Iran’s key oil and financial services industries – depends on a deal being reached that would lead Iran further away from its proximity to the creation of a nuclear bomb – essentially limiting the Islamic Republic to a nuclear programme that is explicitly appropriate for no more than civilian ambitions.

The deadline for such a deal is July 20th . Despite caterwauling from hardliners in Iran on one side, and those in Israel and the US Republican party on the other, sounds of surprising harmony have issued from the negotiators themselves. A treaty is said by White House insiders to rank first on Obama’s list of foreign policy objectives. (Responsible for the 2012 escalation in sanctions, the President’s overtures to Rouhani provide a textbook example of “sweet and sour” diplomacy).

It is in this context that the cautious reconciliation of Iran and Western powers promises most. Military co-operation is unlikely to go far. The commander charged with helping Iraq’s Shia government resist the ISIS surge in its northern territory, Qassem Suleimani, has been personally subject to US sanctions, and his role in supporting Assad and Hezbollah makes any shared operations with Western armed forces something of a remote possibility.

Still, the return of a British embassy to Iran is a concrete sign of progress in a historically strained relationship. Khamenei blamed the “diabolical” British for inciting unrest after the Green Revolution of 2009. It looks as if the Supreme Leader is willing to park his distaste for the West, at least temporarily. Many more obstructions block the path to a nuclear détente whose chances Obama never set higher than 50:50. But if there is one positive to be gleaned from the barbarism of Isis, it is that, with a common enemy unsettling the Middle East, all sides have an added incentive to hammer out an agreement.