The United States president scored one major success and suffered one major defeat at his inaugural United Nations General Assembly, writes Graham Usher in New York Barack Obama had a good week at the UN but a bad one on its sidelines. Before heads of state at the General Assembly, he pledged a "new era" of American engagement with a world body his predecessor had spurned. He steered through a unanimous Security Council resolution on nuclear disarmament. And -- spurred by the "revelation" that Iran was building a second uranium enrichment plant in defiance of UNSC resolutions -- he marshalled a new coalition of states behind his demand that Tehran "come clean" on all parts of its nuclear programme or face sanctions. But outside the Assembly he ran into the iron wall of Israel's refusal to freeze its illegal colonisation of Palestinian land, ending all chance of an early resumption of a Middle East peace process. The US president's debut before the UN was dominated by Iran and undermined by Israel. For four months his administration had predicated an Israeli settlement freeze in the occupied territories as the key to Arab re-engagement in a peace process. Binyamin Netanyahu, Israel's prime minister, refused the trade. On the contrary, he oversaw what one former US negotiator called a "settlement boom" in the occupied territories, authorising 4,000 housing units in the West Bank and excluding East Jerusalem from even a "slowdown". And he faced down the president. Obama -- at a terse round of meetings with Netanyahu and Palestinian President Mahmoud Abbas in New York on 22 September -- called on both sides to "move forward". But he dropped all talk of a freeze, calling instead for Israel to "restrain" settlement activity. He also called for a re- launching of permanent status negotiations "without preconditions", accepting another Israeli demand. For Netanyahu, "preconditions" include issues like Jerusalem and the right of return for Palestinian refugees. Abbas met these shifts in the US position with dismay. "How is it conceivable that negotiations be held on borders and Jerusalem at the same time as Israeli bulldozers are working to... create a new reality and impose new borders as Israel desires?" he asked the General Assembly on 25 September. "How can there be negotiations without agreement on the terms of reference and an objective on which the whole world unanimously agrees: namely, ending Israel's occupation of 1967 to establish a state of Palestine?" Obama had no answer to either question. Yet while his sole strategy for reviving the peace process sank like a stone, he watched his new "engaged" policy to confront Iran on its nuclear programme rise from the dust. On 21 September Iran informed the UN's International Atomic Energy Agency (IAEA) that it had built a second uranium enrichment plant in addition to an acknowledged site at Natanz. Under several UNSC resolutions Iran is supposed to end all enrichment. It should also inform the IAEA of any new plant from the moment of design, not just when it was ready to receive nuclear material, say analysts. So what forced the disclosure? According to the US media, American, French, British and Israeli agents had been tracking the plant at a Revolutionary Guard underground base near Qom "over several years". They had intelligence that the "small, hidden" site could contain 3,000 centrifuges or enough to make weapon fuel, say analysts. Faced with imminent exposure, Iran preferred pre-emption. Obama preferred diplomacy over grandstanding. Rather than go public immediately on the second site, he used the information to try and persuade Security Council members Russia and China to back his contention that any political engagement with Iran must be steeled with the threat of sanctions. Both had been reluctant to endorse any kind of stick. Engagement worked, at least with Russia. Lubricated by a recent Obama decision to scrap a Bush-era plan to deploy US missiles in central Europe, Russian President Dmitri Medvedev said he was "seriously concerned" about the discovery of a second Iranian uranium enrichment site. He called on Tehran to show "convincing proof of its intention to develop nuclear energy solely for peaceful aims". China too urged Iran to "work within the IAEA framework". The result was a rare unity between the US, Britain, France, Russia, China and Germany, calling for a "serious Iranian response" at crucial talks in Geneva on 1 October. Stewarded by Obama, the "negotiations" are actually an ultimatum: either Iran grants "unfettered access" by IAEA inspectors to all sites, computers, documentation and scientists related to Iran's nuclear programme or it will face sanctions, perhaps "crippling" ones. According the US officials Tehran will have "weeks" to allow access to the Qom site and until Christmas to cooperate on the rest. Iran is unlikely to comply with all or even most of these demands. Its initial response was defiance, with Revolutionary Guards test-firing medium-range missiles and staging war games "to improve the Islamic Republic's armed forces' defence capabilities". But the American offensive has rattled what was an already shaken regime. And a new raft of sanctions backed by Russia and China can only aggravate cracks in a ruling establishment that is becoming isolated abroad, feared regionally, roiled in economic and political crises at home and loathed by large parts of its own people. In the long, positional war between America and Iran over its nuclear programme Obama has clearly won the latest round. He has done so by working through (rather than against) the UN Security Council and in the name of an international legitimacy Washington has consistently ignored in its own actions or those of Israel. "International law is not an empty promise... Those nations that refuse to live up to their obligations must face consequences," Obama told the General Assembly, to applause. It remains to be seen whether such principles will be applied in a more consistent fashion in the future.