From the American point of view this week’s developments are exasperating and alarming. The Iranian refusal to acknowledge Thursday’s deadline to halt its nuclear activities was not a great surprise, although brinkmanship, of the kind the UN Security Council was practising, can produce unexpected results.

Tehran continues to maintain that its work is purely for power generation, but Thursday’s hard-hitting report by the International Atomic Energy Agency listed all the evasions that have led other governments to accuse Iran of a covert weapons programme.

More worrying for America, Iran’s defiance revealed that the impetus for sanctions among Tehran’s diplomatic adversaries had ground to a halt over the summer.

In theory they will all now sit down, beginning next week, and try to agree some sanctions (or “measures”) against Iran. But although Russia and China have signed up to the principle, in practice anything they back is likely to be innocuous. Where does that leave President Bush, and his declaration that a nuclear-armed Iran would be “intolerable”? Or Israel, which fears that it would be a prime target of those weapons?

The formal Israeli position is unchanged. “We really hope that this international community will solve this problem diplomatically,” a spokesman said yesterday. “We are well aware of the importance of putting an end to the problem, but I will not even talk about what will happen [if diplomacy fails].”

But some analysts argue that the popular speculation about an Israeli attack on Iran’s nuclear installations is misplaced. It is prompted, of course, by Israel’s strike on Iraq’s Osirak reactor in 1981. But the Iranian programme is far larger, dispersed and likely hidden.

“I don’t think an Israeli strike is likely at all,” says Mark Fitzpatrick, proliferation analyst at the International Institute for Strategic Studies, a London-based think-tank. “Israel could not do it as well as the US could do it.” An Israeli attack would reap all the disadvantages of a US attack in terms of reprisals, more so if it provoked direct retaliation. But it would secure fewer benefits in that Israel would not be able to knock out any sites.

The only circumstances in which that calculation would change, Fitzpatrick suggests, would be if Israel concluded that diplomacy had failed, that the US would not act and that failure to strike would risk its annihilation. “That discussion wouldn’t happen for several years,” he said.

That is a plausible argument, which has an air of melodrama now, but may not in a year’s time. The signs of whether diplomacy will work are not promising: intransigence, backed by wild populist appeals on the Iranian side; and muddy indecision among the permanent members of the Security Council (Britain, the US, France, China and Russia).

If a year passed with little progress, then it is conceivable that quiet discussions about military action might begin within the Bush Administration, where the threat is taken seriously and intimately.

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