Europe's stuttering efforts to ensure that Iran does not build a nuclear bomb are due to resume Wednesday with a new round of high-level talks, but the shadow of upcoming presidential elections in Tehran has dimmed hopes of progress, say experts following the negotiations.
Three European Union foreign ministers will meet the top Iranian nuclear negotiator, Hassan Rowhani, in Geneva for what Iranian Foreign Minister Kamal Kharrazi said last week is "a last chance" of compromise to defuse a mounting crisis with the West.
The Europeans have warned that if Iran makes good on its threat to resume nuclear fuel enrichment - a key step in producing a bomb - they will refer the country to the UN Security Council for possible sanctions.
But with Iranian presidential elections due on June 17, "the Iranians will fudge and dither as much as possible" at the Geneva meeting, "and the Europeans will want to wait and see if a new president makes a difference," says Ali Ansari, an analyst with the Royal Institute for International Affairs, a think tank in London.
Though neither side wants to precipitate a confrontation at this stage, the prospects of a compromise look slim. The man tipped to become Iran's next president, Akbar Hashemi Rafsanjani, pledged in an interview with Reuters last week never to abandon the nuclear program.
"It is like giving away part of our territory," he said.
Negotiations between the EU and Iran to secure guarantees that Tehran will not use its nuclear-energy program to further the development of a nuclear weapon began last November, when Iran agreed to temporarily suspend the enrichment of uranium.
Since then, the talks have run up against a fundamental problem: Iran insists on its right under the Nuclear Non-Proliferation Treaty to enrich fuel for power-generation purposes, and suggests that international inspections and other measures could ensure it was not diverting fuel for military use.
The Europeans, however, backed by the United States, say Iran's 18-year history of concealing parts of its nuclear program means that only a cessation of fuel enrichment would provide sufficient guarantee that Iran was not trying to build a nuclear bomb.
So far, the talks have focused on European offers of trade and aid deals as an incentive for Iranian compliance with Western demands. In the background has been the threat of UN sanctions and the possibility of eventual US military action.
The only offers that have been made public, and endorsed by Washington, have been to open talks for Iran's entry into the World Trade Organization (WTO) and to provide spare parts for Iran's aging fleet of Boeing passenger jets.
Senior Iranian officials have dismissed these proposals as derisory.
Some independent analysts suggest that only the prospect of some sort of security arrangement with the US might induce Iran to give up its nuclear weapons ambition. "They want a dialogue on security and some confidence-building measures with America," says Valerie Lincy, who follows Iran's nuclear program for the Wisconsin Project on Nuclear Arms Control.
"Rather than the narrowly defined technical issues that Europe can discuss, the big US carrot comes from the security angle," she adds.
Washington, however, has so far rebuffed European pleas to involve itself more directly in the negotiations.
"There is no reason to believe that extra incentives offered by the United States at this point would make a difference," US Undersecretary of State Nicholas Burns told the Senate Foreign Relations Committee last week.
"We don't have any reason to think that if the US were at the table, the Iranians would be any more open," he added.
Critics of the United States, however, suspect that Washington is hanging back because it has not decided whether its avowed policy of regime change means a change of regime or a change in the way the current Islamic republic behaves.
"The core issue for the United States is that they don't know what they want to do," charges Dr. Ansari. "And the threat of force is all they have to offer."
Europe's faith in diplomacy, on the other hand, is likely to be further tested if the talks continue after next month's elections.
The hard-line Guardian Council in Tehran, which oversees elections, on Sunday selected only six candidates as eligible to stand for president, at first rejecting the best known reformists.
After Iran's supreme leader, Ayatollah Ali Khameini, called on the Council to review its decision, the Council approved two prominent reformers. But Mr. Rafsanjani, a two-time former president, remains the favorite to win the elections.
A consummate dealmaker, Rafsanjani might have the influence and authority to rein in the most conservative forces and push through an agreement with the West on nuclear issues, some observers say.
Even if that turns out to be a vain hope, the foreign ministers of Britain, France, and Germany are unlikely to break off the negotiations Wednesday, says Ms. Lincy.
"It's worth waiting," she argues. "The talks could fall apart now or they could fall apart after the elections. But it is worth seeing how things evolve when the dust settles."