The referring of Iran over its nuclear intentions to the UN Security Council was as inevitable as it was necessary. The decision reached by the International Atomic Energy Agency on Saturday, while welcome, was not as categorical as it might appear. The IAEA has set provisional conditions for Iran to be placed in the dock, yet allowed for movement to occur before its next meeting on March 6 in Vienna. Not only the leadership of the IAEA but also a number of countries on its board plainly wish that some sort of deal would emerge by then to defuse this crisis. The presumed vehicle for such an escape is an understanding between Moscow and Tehran, which would allow nuclear enrichment, conducted in Russia, for Iran’s benefit.

It is understandable that hope is invested in this solution. The options for Iran are hardly appealing. The idea of permitting this exceptionally un- reliable regime to control nuclear weapons is appalling. It could not be assumed that Tehran wanted an arsenal solely as a status symbol or as a deterrent. Israel, in particular, fears that a theocracy would not hold the same regard for the Cold War maxim of mutually assured destruction as either a democracy or a secular dictatorship.

Avoiding that outcome is challenging. Estimates of how long an unrestrained Iran would take to construct a deployable device range widely, from months to more than a decade. There is doubt as to whether a “surgical strike” would eliminate this menace, and a wholesale attempt at regime change via full-scale military intervention does not look plausible. The optimists argue that, “in time ”, Iran’s relatively youthful population will not tolerate the irresponsible fanaticism of the likes of Mahmoud Ahmadinejad, the hardline President. It is not clear, alas, whether time is something that the world has the luxury of savouring.

Hence the obvious interest in Russia. It is not impossible that an arrangement could be found that would allow Iran, despite what it says today about suspending all voluntary co-operation with the IAEA, to begin to act in a manner that inspires a little more confidence. There is, nonetheless, a danger that the desire to avoid an extremely awkward confrontation with Iran will mean that the EU — especially — hails anything that Vladimir Putin can negotiate as a triumph.

It is increasingly clear that Moscow realises that a nuclear-armed Iran would pose a serious threat to its own security. China, too, has begun to play a more responsible role, knowing that conflict with Iran would compromise its supplies of energy. If Iranian scientists were permitted to enrich uranium in Russia, then that would have to be undertaken with the tightest international supervision. The suspicion that the knowledge secured might be repeated in Iran means that any “settlement” with Tehran would demand a more intense system of investigation than exists now, and with a firmer ethos than the lenient Dr Mohamed ElBaradei, the Director-General of the IAEA, has too often provided. Britain should support the United States in seeking to hammer out a detailed accord with no loopholes if Russia and Iran announce that they have reached an agreement. The international community should wish to ensure that Iran does not control nuclear weapons. It must not settle for any “compromise” that merely postpones the moment.