http://www.telegraph.co.uk/opinion/main.jhtml?xml=/opinion/2008/10/24/do2406.xml

Where will it end, this procession of the great, the good and the not-so-good showing their support for Barack Obama’s bid to become President? Colin Powell, the former Secretary of State, half the Tory front bench and Boris Johnson, the London Mayor, have all declared in favour of the Democrats’ nominee. But perhaps the most revealing was yesterday’s confirmation that Mr Obama is the preferred candidate of the Islamic Republic of Iran.

You can sort of understand why Mr Powell, who was humiliated by the hawks in the Bush Administration over Iraq, might feel more at home with a Democratic president, while the Tories just want to be on the winning side, irrespective of policies. But Iran?

An insight into Tehran’s thinking was provided by Ali Larijani, the speaker of the Majlis, the Iranian parliament which is dominated by conservative hardline followers of Ayatollah Khomeini. The Iranians, say Mr Larijani, favour Mr Obama because he is “more flexible and rational” than John McCain, whose attitude towards a country that still tops the State Department’s list of terrorism-sponsoring regimes was given away by his “Bomb Iran” version of the Beach Boys’ classic Barbara Ann.

By “more flexible and rational” Mr Larijani means, of course, that an Obama White House is less likely to bomb Iran for its failure to halt its nuclear enrichment programme.

It is now more than five years since Iran first came under international pressure to halt the development of its nuclear programme, but despite threats and cajoling, Iran has made no meaningful concessions to the West, while continuing with its drive to be self-sufficient in the production of fissile material that could ultimately be used to make atom bombs.

Iran has been enriching uranium at its facility at Natanz for 18 months, and even the most dovish observers concede that, at the present rate of progress, Iran should be able to produce enough fissile material for a nuclear warhead by next year.

Whether Iran is still pursuing its attempts to develop nuclear weapons is hotly debated among the West’s intelligence agencies, with the body of available intelligence now contradicting last year’s CIA National Intelligence Estimate, suggesting Iran had halted its military programme in 2003.

In short, the West is rapidly reaching the moment when it has to decide whether Iran should be left to get on with acquiring the technical and practical know-how to build nuclear weapons, or take effective action to stop it – such as bombing its key installations.

Mr Larijani provided insight into how Tehran assesses the threat posed by Washington when he said America was now far too preoccupied with the global financial crisis to bother with Iran. “The risk was low before, but now I am 100 per cent certain that the United States will not unleash a war against Iran.” That is, if Mr Obama becomes president, he might have added.

Mr Obama may have made some rousing comments when he addressed a pro-Israel lobby in Washington in June, telling his audience that he would do “everything in my power to prevent Iran from obtaining a nuclear weapon”, but he has also made it clear that he wants to negotiate with the Iranians rather than confront them. Mr McCain, on the other hand, favours robust action, starting with a tough sanctions regime and, if that fails, military action.

Small wonder, then, that Iran favours Mr Obama for the White House, especially as the Democrats have a disastrous record of negotiating with Iran and getting nothing in return, dating from Jimmy Carter’s ineffectual attempts to free the Americans held hostage after the storming of their embassy in Tehran in 1979.

To paraphrase Michael Howard, the former Conservative leader: if the Bush Administration had known in 2003 what it knows now, both about Iran’s involvement with nuclear proliferation and its support for Islamist terrorism, it might have preferred to make Iran its principal target in the war on terror, rather than Saddam Hussein’s Iraq.

Iran now poses a far greater threat than it did in 2003, when its nuclear programme was nowhere near as advanced.

Which is why, irrespective of who wins next month’s presidential contest, the Iran file will be at the top of the list of national security issues facing the new president. Mr Obama’s preference might be for more talking, which is precisely why Tehran is backing his candidacy. But he will not have that luxury. So far as Iran is concerned, the time for talking has passed. It’s time now for some action.