However, none seemed quite sure what the problem was, let alone what the solution might be.

Only Senator Barack Obama, the likely Democrat nominee, offered something concrete: If elected, he would invite his Iranian counterpart President Mahmoud Ahmadinejad for unconditional talks.

This is what Obama said at a press conference: "Preconditions, as it applies to a country like Iran, for example, was a term of art. Because this administration has been very clear that it will not have direct negotiations with Iran until Iran has met preconditions that are essentially what Iran views, and many other observers would view, as the subject of the negotiations; for example, their nuclear program."

Talking without preconditions would require the US to ignore three resolutions passed unanimously by the United Nations' Security Council, making a set of demands from the Islamic Republic.

Before starting his unconditional talks with Ahmadinejad, would Obama present a new resolution at the Security Council to cancel the three that he Islamic Republic president does not like? Or, would Obama act in defiance of the UN, thus further weakening the authority of the Security Council?

The preconditions that Ahmadinejad does not like and Obama promises to ignore were not set by President George W Bush.

They were decided after the International Atomic Energy Agency (IAEA) reported the Islamic Republic to be in violation of the Nuclear Nonproliferation Treaty (NPT) and, acting in accordance with its charter, referred the issue to the Security Council.

Dismissing the preconditions as irrelevant would mean snubbing America's European allies plus Russia and China, all of whom participated in drafting and approving the resolutions that Ahmadinejad does not like.

Such a move would make a mockery of so-called "multilateral diplomacy" which the Bush administration is supposed to have ignored.

It is clear that Obama has not asked British Prime Minister Gordon Brown, German Chancellor Angela Merkel and French President Nicola Sarkozy what they think of the US suddenly changing course and granting Ahmadinejad's key demand in advance.

It is quite possible that Obama has not been properly briefed about the "preconditions" he gets so worked up about.

He cites Iran's "nuclear programme" as a precondition. This is not true. No one has asked, or could ask, Iran to stop its nuclear programme-period. On the contrary, Iran's membership of NPT gives it the right to seek help from other signatories, including the US, to access the latest technology in developing its nuclear industry for peaceful purposes.

The Security Council is not asking the Islamic Republic to do something dishonorable, humiliating or illegal.

All it asks Ahmadinejad to do is to stop cheating, something the Islamic Republic itself has admitted it did for 18 years. The Security Council invites the Islamic Republic to "suspend", not even scrap, a programme of uranium enrichment clearly destined for making bombs in violation of the NPT.

Iran does not have a single nuclear power station and thus does not need enriched uranium, except for making bombs. Its sole nuclear power station under construction, is scheduled to be ready by the end of 2009. That station, however, cannot use the type of uranium that Iran is enriching. The enriched uranium it needs is of a different scientific code, one supplied by Russia, which is building the project, for the next 10 years. ( Russia has offered to provide the fuel needed for the entire life of the station, that is to say 37 years.)

Another precondition is for Tehran to explain why it is building a heavy water plant at Arak when it has absolutely no plans for plutonium-based nuclear power stations. The Arak plant's only imaginable use is to produce material for nuclear warheads.

Finally, the IAEA and the Security Council are asking Tehran to allow international inspectors access to all sites related to the nuclear project, in accordance with Iran's obligations under the NPT.

The minimum show of goodwill on the part of Ahmadinejad would be to implement the UN resolutions before he goes to the White House for talks with President Obama on other issues.

Obama's position has helped ease domestic pressure on Ahmadinejad to listen to the UN and the IAEA. The Islamic Republic president is telling his domestic critics to shut up until after the US presidential election. Why should Iran make concessions that a putative President Obama has already dismissed as unnecessary?

Paradoxically, Obama's stance encourages Ahmadinejad to harden his position. And that could make it more difficult for a putative President Obama to deal with what a regime he describes as "an enemy."