The EU3 -- Britain, France and Germany -- proposed a package of incentives to offer Iran, understood to include help with building light water reactors that do not produce plutonium waste, a nuclear fuel bank that would guarantee Iran access to reactor fuel, and a series of security guarantees.
However ahead of the talks disagreement between the six participants threatened to scupper progress, with the United States understood to be reluctant to offer security guarantees and Russia and China concerned at the inclusion of a threat of sanctions.
The negotiations appeared to do little to resolve such differences. A spokesperson for the British Foreign Office in London, which hosted the talks, hailed "constructive and valuable discussions" but acknowledged that further negotiations would likely be necessary before ministers could finalize a strategy.
The "complex and sensitive" nature of the discussions prevented further comment, he said.
The debate on how best to cope with Iran's nuclear programs -- which Tehran insists are for peaceful energy purposes only -- is consuming politicians and analysts across the globe.
Speaking at a forum on the issue in London's House of Commons last week, former Foreign Secretary Malcolm Rifkind, a Conservative parliamentarian, said that while diplomacy was "undoubtedly a sensible way forward," the various governments involved had to address what action they would take if negotiations failed.
Not to do so would be "positively dangerous," he said, as Iran's leaders needed to know that the international community had "a plan B."
Those who suggested that it was preferable to live with a nuclear Iran than take military action were underestimating the scale of the threat, he argued.
The advent of a nuclear-armed Iran would further destabilize the Middle East and likely trigger a nuclear arms race, particularly among regional powers such as Saudi Arabia and Egypt, he continued. "The implications are dreadful."
"In my view we need a radically different strategy to that which is currently being pursued," Rifkind said. He recommended a "carrot and stick" approach, but added that both needed to be "more credible and significant" than they were at present.
Iran did have legitimate security concerns which needed to be addressed, he said. It had previously been attacked with chemical weapons by Saddam's Iraq -- an aggression supported by much of the West, including the United States -- and saw itself as surrounded by American dependencies in Iraq and Afghanistan, U.S. allies in Turkey and Saudi Arabia and a nuclear Israel. It was subject to a U.S. policy of regime change and had been described by President George W. Bush as part of the "axis of evil," he added.
While these denunciations might or might not be justified, Rifkind continued, "what is unhelpful is that it has created an Iranian government that lacks confidence in its own security, both as a regime and as a nation."
The United States was the one country that could reassure Iran, by offering it normal diplomatic relations, dropping current trade sanctions and rescinding its policy of regime change, he said. The United States had overcome decades of bilateral hostility to resume normal relations with China and Libya, he noted; it should be "equally bold" with Iran.
This should be offered in exchange for Tehran's permanent renunciation of any nuclear weapons ambitions and complete cessation of its uranium enrichment program, he said.
However in order to work, such incentives had to accompanied by a "credible stick," Rifkind continued. It had to be made clear to Iran that if such a generous offer was rebuffed, the Security Council would impose economic and financial sanctions. If Russia and China declined to back such a move, the Western powers should implement them unilaterally, particularly boycotts by banks and other financial institutions. "Such measures would do serious damage to the Iranian economy in a relatively short period of time," he said.
But, he stressed: "If such measures still do not have the desired impact, military action might have to be considered. Even if it did not destroy Iran's weapons capability, it might sufficiently degrade it to make such a policy worth considering."
But Tony Benn, a former Labor cabinet minister and a hero of the anti-war movement, said that any military action against Iran would have "appalling short-term and long-term consequences." Strikes against the country's nuclear facilities would be "playing with fire in a big way" because of the potential nuclear effect and the possibility of sparking a religious war.
He said that the United States' current threats against Iran were counterproductive as Tehran would view them as the case-in-point for acquiring nuclear weapons. The regime knew well that the United States would never attack nuclear-armed countries, a fact exemplified by the case of North Korea, he said.
Such threats were also strengthening Iranian President Mahmoud Ahmadinejad, he said, as "foreign threats always strengthen existing governments."
Meanwhile Hugh Dyke, the Liberal Democrats' European Union spokesperson, said that while there was indeed a "latent danger" in Iran's nuclear development that had to be dealt with, the West also had to address the perception of double standards that pervaded the Muslim world. Iranians saw it as deeply unfair that the United States felt it had the right to interfere in their nuclear energy program and political system, while Washington and Tel Aviv broke international law "all the time," he said, asking: "When is the U.S. going to pressure Israel to respect international law?"
He advised against premature sanctions before all diplomatic avenues had been exhausted, saying this would antagonize the moderates within Iran.
Donald Anderson, the former Labor chairman of Parliament's Foreign Affairs Committee, said that recent military estimates indicated that strikes would only delay Iran's nuclear development by a year or two. Such a result was not worth the consequences, he suggested.
But Jonathan Paris, formerly Middle East fellow on the U.S. Council on Foreign Relations, said the dispute that Iran had picked was "an assault on liberal democracies of the West" and needed "robust confrontation." He dismissed suggestions that Washington should negotiate directly with Tehran, saying that this would legitimize the current leadership and undermine forces for democratic change within Iran.
However some analysts are pushing the U.S. administration to respond to Ahmadinejad's recent letter to Bush and to reported Iranian requests for direct negotiations.