Discovering Iran's secret nuclear plant has wiped off Mahmoud Ahmadinejad's smile

If nothing else, the disclosure that Iran is building yet another underground nuclear facility has had the welcome effect of wiping the smile off Mahmoud AhmadinejadMahmoud Ahmadinejad's faceUntil the Obama administration dropped the bombshell that it knew what the Iranian regime was up to, Mr Ahmadinejad had been enjoying himself, provoking mass walkouts from the United Nations General Assembly in New York after his claims the Holocaust was a myth.He had even managed to persuade some of the more gullible delegates that Iran would take a constructive approach to this week's scheduled talks over the future of its nuclear programme, which are due to take place in New York on Thursday.Holding court at his hotel, Mr Ahmadinejad said he was looking forward to "free and open" discussions during this week's meeting with six world powers on Iran's nuclear programme.But by Friday, Mr Ahmadinejad's composure looked shaken when he appeared at a news conference shortly after President Barack ObamaBarack Obama had disclosed that Iran had been developing a second uranium enrichment facility near the holy city of Qom without bothering to inform the UN's International Atomic Energy Agency what it was up to.Given Iran's previous track record of concealing vital details of its nuclear programme from the UN, the disclosure that Iran had been forced to admit it had embarked on another undeclared nuclear site has severely damaged Mr Ahmadinejad's credibility at a crucial moment in the international stand-off over Iran's nuclear ambitions.The origins of the current crisis date to the disclosures seven years ago that Iran had built an industrial scale, underground uranium enrichment facility at Natanz that could ultimately provide Tehran with the capability to build an atomic bomb. Despite intense diplomatic efforts by the EU3 – Britain, France and Germany – to get Iran to freeze its enrichment activities, Mr Ahmadinejad has managed to string out the negotiations while at the same time maintaining the pace of Iran's nuclear programme. Many experts now believe Iran will have enough fissile material to build a warhead within a year.To judge by his relaxed demeanour last week, Mr Ahmadinejad was confident that he would be able to lure the Obama administration into the same diplomatic trap. Since coming to power last January, Mr Obama has gone out of his way to extend the hand of friendship to Tehran.Mr Obama is so keen to make a break with the hostility that has characterised US-Iranian relations for the past 30 years that he has agreed to participate in direct negotiations with Iran for the first time since the 1979 revolution.But if Mr Ahmadinejad thought that, when the talks finally begin on Thursday, he could once more indulge in the politics of procrastination that have served the development of Iran's nuclear programme so well, he has received a rude wake-up call.Far from being seduced by Mr Ahmadinejad's hints that Tehran is interested in forging better relations with the West, Mr Obama has shown that he is rapidly losing patience with Iran's grandstanding.Apart from disclosing details of the Qom project, Mr Obama made it clear during his UN address that he wants to make nuclear proliferation a key component of his foreign policy. If the US and other Western powers, such as Britain, are prepared to make concessions on their stockpiles of nuclear weapons, then why not Iran?But rather than appearing as an honest broker with whom Washington can do business, Mr Ahmadinejad, in his various US television interviews, came across as shifty and disingenuous. Interviewed by the veteran CNN presenter Larry KingLarry King, Mr Ahmadinejad provided a strong hint as to how Iran intends to approach Thursday's talks when he launched a personal attack on Mr Obama. He claimed that the US president's accusations regarding Iran's nuclear programme were "baseless", and a violation of his commitment to work for a peaceful resolution of the conflict with Iran. But it is Mr Ahmadinejad who is likely to find himself under sustained pressure when Iran gives its response to an offer from six world powers – the EU3, plus America, China and Russia – to end the international stand-off. With David MilibandDavid Miliband, the British Foreign Secretary, refusing to rule out military action against Iran, and Dmitry MedvedevDmitry Medvedev, the Russian president, making noises that Moscow is prepared to support a new round of sanctions against Tehran, international opposition to Iran's nuclear programme is undoubtedly hardening. Mr Ahmadinejad might try to play down the impact sanctions are having on Iran, but with unemployment at more than 30 per cent and inflation in double figures, further sanctions would increase the government's woes.Public disquiet with Mr Ahmadinejad's economic performance was the driving force behind the pro-reform protests that brought the country to a standstill last summer. Mr Ahmadinejad can expect more of the same unless he can demonstrate he is serious about making peace with the West.