Only genuine engagement can stop Iran becoming the world's tenth nuclear-armed state, writes Graham Usher in New York The glacial confrontation between the West and Iran's nuclear programme shifted, a bit, last week, though not in the direction that Washington is pursuing. On 30 March Barack Obama said he was hopeful a fourth round of Security Council sanctions against Tehran could be ready by spring. "I'm interested in seeing that [sanctions] regime in place in weeks", he said in Washington. He was standing alongside French President and fellow permanent Security Council member Nicolas Sarkozy, who added: "The time has come to take decisions. Iran cannot continue its mad race" to develop nuclear arms. The American president's advocacy of "aggressive" sanctions seemingly ends his policy of "engaging" Iran over its nuclear programme, one most analysts judge to have been a failure. The latest rebuff came in February in a report by the United Nations' nuclear watchdog, the International Atomic Energy Agency (IAEA) which now agrees that Iran may be trying to make a nuclear bomb. But how likely is a new SC sanctions resolution, given the past opposition of one permanent member, China, and the reluctance of another, Russia? Obama admitted there was "not yet... international unanimity" on another round. "It's still difficult... because Iran is an oil producer, and there are a lot of countries around the world that, regardless of Iran's offences, are thinking that their commercial interests are more important to them than these long-term geopolitical interests." China is among them: with trade totalling $36.5 billion and Iran supplying 11 per cent of its oil and gas Beijing has a lot to lose from harsh sanctions. But, together with Russia, it is also unconvinced more sanctions will do anything to thwart Iran's drive to the bomb, if that is what Tehran seeks. They have a point. Iran has been under sanctions of one sort or another for 30 years, yet it has built a formidable nuclear industry. It has been under SC sanctions since 2006, yet since then it has probably deepened the military aspects of the programme, suggests the IAEA. But this policy cannot work for one simple reason. For the present Iranian regime the capacity at least to manufacture the bomb is an imperative of national security, reasoning that only a state with nuclear weapons is immune from a US, Israeli or other attack. If that is the mindset, no degree of sanctions will deter it, any more than sanctions deterred Pakistan assembling a bomb against a nuclear India. Despite this logic, the US still hopes that very, very strong sanctions, including Iran's main partners, could work. But unless China and Russia were to be won over to a new SC resolution, the sanctions are likely to be so modest as to be derisory. Both countries have already ruled out "crippling" sanctions against Iran's energy sector, shipping lines and oil and gas exports. They are even worried by measures that hurt Iran's Revolutionary Guards, since this looks less like curbing proliferation than promoting regime change. Any new round of SC sanctions is likely to be ineffectual, delayed and with less than unanimous support from a Security Council that includes not only Russia and China, but Turkey, Lebanon and Brazil, all of which oppose sanctions. Why then is Obama so aggressive in pursuing them? One argument is that sanctions are now the only way to "restrain" Israel from undertaking a military strike. US emissaries have been making this case in Beijing and other capitals. But there is far more smoke than fire about this issue. First, there is history. Since 1956, Israel has taken no major military action without America's consent, including the wars in Lebanon in 2006 and in Gaza in 2008-9. Aside from lunatic fringes like Sarah Palin, no one in the US political-military establishment thinks a military strike against Iran would be anything other than insane for a country already fighting wars in two countries in the region and failing to make peace in a third. Recent months have seen a procession of senior US officials to Jerusalem warning Israel that it does not have an amber American light for an attack on Iran, let alone a green one. The current US-Israel impasse over Jewish settlement in East Jerusalem has hardened that veto. "You think we overreacted to a housing spat in Jerusalem? Try bombing Iran", wrote commentator Stephen Hayes in America's Weekly Standard recently. Second, an Israeli strike could only damage Iran's nuclear installations, which are dispersed, underground and in some cases unknown. But Iran's retaliation is completely predictable. At the very least it would seal off the Hormuz Strait in the Persian Gulf: this would block much of the world's oil supply, send prices soaring and tip a parlous international economy into freefall. Thus it wasn't only Tehran Obama was warning when he said, in Washington, that: "a conflict in the Middle East, as a consequence of Iran's actions, could have a huge destabilising effect on the world economy at a time when it's just coming out of a very deep recession." Finally, an Israeli strike on Iran would unite the entire Islamic world, including the peoples of those "moderate" Arab states the US has so laboriously marshalled against the "Iranian threat". A war lit by Israel, with the perceived connivance of Washington, would leave that coalition in tatters. With sanctions ineffective, and a military hit impossible, it is clearer than ever that there remains only one way to stop Iran becoming the world's tenth nuclear-armed state. And that is for Washington to engage it not only on the nuclear programme but on those matters Iran deems vital to its own national security; namely, US military bases in Iraq, Afghanistan, Pakistan and the Gulf that could be used to launch regime change and an Israeli nuclear arsenal that is targeted not only on Iran but every other regional capital. The road to a nuclear-weapons-free Iran lies through a nuclear-weapons-free Middle East -- not the other way round.