PARIS - European nations are watching with a mixture of bemusement and disquiet as talk grows of a United States or Israeli strike against Iran to derail its nuclear weapons programme.
The media-channelled drumbeat of an operation to wreck Iran's nuclear sites is being dismissed in European capitals mostly as a bluff - but with the caveat that if a strike does take place, the repercussions could resound catastrophically for years to come.
Markus Kaim, an analyst with a Berlin think-tank, the German Institute for International and Security Affairs, said a "small window" remained open for diplomacy before Iran crossed the nuclear threshold, which according to a US intelligence assessment could be in 2010 or 2011.
"It would be a disaster if America now pursued a military option," said Kaim. For the time being, "The people in Washington dreaming about the military option" remain in the minority.
"After Iraq, after the difficulties in Afghanistan and the divide in transatlantic relations, are these people really prepared to risk another foreign policy disaster? It is one thing to talk about a military strike, another to talk about [its impact on] the free flow of oil from the Persian Gulf and the overall regional security in the Middle East."
Speculation of a strike has risen after Iran responded defiantly to a new United Nations Security Council resolution and to measures unveiled last week by the European Union aimed at reining in its uranium enrichment programme.
The EU measures include a freeze on the assets of the largest Iranian bank, Melli, which is accused of providing services to the Iranian nuclear and ballistic missile programmes.
Britain, China, France, Germany and Russia are offering the prospect of negotiations provided the enrichment activities are halted.
Iran would get help to develop nuclear power stations and be guaranteed fuel for them, and could also be offered trade concessions, including the possible lifting of US sanctions preventing it from buying new civilian aircraft and parts. Iran has yet to respond to this offer.
The New York Times reported that more than 100 Israeli warplanes took part in a rehearsal in June that appeared aimed for a possible long-distance operation against Iran, and some US commentators have mulled whether President George W. Bush would mount a strike, or support an Israeli one, before he leaves office.
A French intelligence source said he did not believe that, at this point, the Israelis were serious about doing such an operation by themselves as they lacked the firepower. It was far more in Israel's interest to have the Americans do the job, he said.
Iran is believed to have three main nuclear facilities, but other sites are scattered around the country and could be underground, which would require "thousands" of cruise missiles and bunker bombs, the source said.
If a strike did go ahead, "It may delay Iranian nuclear programme by only two or three years" and at the cost of retaliation against the oil market, strengthening the mullahs and bolstering the standing of extremists throughout the Muslim world, he said.
"It would be a huge mistake."
Robin Shepherd, an analyst at the Royal Institute for International Affairs in London, said the Iranian crisis posed a particular challenge for Europe as it seeks to "portray itself as a serious partner to the US" in the Iranian crisis.
Europe needs Iranian oil and some European countries do very well from trading with Iran. This means European willingness to tighten the sanctions screw has limits.
But, Shepherd said, in the event of a military strike, European unity could crumble. Some countries would accuse the US and Israel of setting a match to the powder keg, while others would "privately celebrate" that someone had taken a stand.
"Europeans still cling to the belief that diplomacy alone will work with Iran."