But some Iranian officials say their nuclear program (which has made substantial progress on nuclear enrichment, despite new sanctions) won't even be on the agenda. And if it is, the political and technical landscape has changed so much in the past year – proof that US efforts have backfired, say analysts – that Iran's hand is stronger going into these talks.
"While Iran is set on pursuing its independent uranium enrichment policy, and when the US is not in a position of starting a new war in the region, time is against Washington," says Kayhan Barzegar, an Iran specialist at Harvard University's Belfer Center for Science and International Affairs.
"Perhaps the Obama administration is now willing to initiate the talks, but it has not reached a final decision yet because it is waiting to see the impact of tough sanctions against Iran," says Mr. Barzegar, contacted in Tehran, where he also serves as a director at the Center for Middle East Strategic Studies. "This is the wrong policy because sanctions will not change Iran's nuclear policy."
The October 2009 nuclear talks yielded a tentative agreement: Iran would export 1,200 kg (2,600 lbs.) of its homemade low-enriched uranium (LEU) – the bulk of its stockpile at the time and theoretically enough to fabricate a single atomic bomb if enriched from 3.5 percent to more than 90 percent. In exchange, it would receive 20 percent enriched nuclear fuel necessary for a small medical research reactor.
Iran ultimately rejected the deal, calling it a ploy to deprive the Islamic Republic of its right to fuel under the Nuclear Non-Proliferation Treaty. So in February, Iran announced it had boosted its own enrichment levels to 20 percent, and would make the fuel itself.
In May, Brazil and Turkey got Iran to sign a virtual replica of the US-backed October 2009 deal. But neither deal required Iran to stop enriching uranium altogether, as demanded by UN Security Council resolutions.
The US dismissed it immediately as not going far enough – considering that Iran had expanded enrichment – and orchestrated a fourth round of United Nations sanctions that passed the next month.
News reports have suggested that the US is preparing an "upgrade" of the 2009 fuel swap deal. It would require Iran to export 2,000 kg of LEU, to take into account that Iran's stockpile has grown to roughly 2,800 kg.
But what started as a confidence-building measure has now turned into a tangled mix of Western motivations and Iranian defiance, complicating the talks that are about to begin.
While Iran has experienced some technical problems – the International Atomic Energy Agency (IAEA) reported that all of Iran's 8,426 centrifuges involved in low enrichment were idle in mid-November – it has also made progress in many areas.
"It's easy if you are sitting at the State Department to say: 'We're steamrolling these guys,' " says Ms. Barzashka. "But at the same time, Iran is pushing forward with 20 percent enrichment. They're pushing forward with their own fuel manufacture."
If reducing Iran's capacity to get a nuclear bomb was a concern, the delayed diplomacy and Iran's inability to secure 20 percent fuel from any other source "have so far given Iran a reason [to go] for higher enrichment, putting it closer to a bomb," she says.
"Sanctions don't push back the nuclear clock, but 20 percent enrichment actually pushes that [clock] forward," Barzashka adds. Iran has already produced about 33 kg of the higher-grade material; if it were able to get the fuel, it would have no reason to enrich to that level.
Iran denies that it is pursuing the bomb, and its top authorities state that Islam forbids nuclear weapons. Frequent inspections by the IAEA have not turned up diversion of any nuclear material, though the UN agency says Iran has not yet fully cooperated in clarifying past design issues.
The new task for negotiators will be creating confidence where little exists, and amid tense rhetoric. Sen. Lindsey Graham (R) of South Carolina in November explicitly called for the military annihilation of Iran's regime, while Iranian President Mahmoud Ahmadinejad accused the West of "thinking as aggressors," adding, "No embargoes can change the Iranian people."
Few analysts believe that sanctions, the default US policy toward Iran for decades, will change Tehran's nuclear calculus.
"If the US is serious [about] a diplomatic solution, it must recognize Iran's right to enrich uranium on its soil and accept Iran's indispensability for maintaining stability in the Persian Gulf," wrote Barzegar in the latest issue of the Bulletin of the Atomic Scientists. "Iran, in turn, will reciprocate by agreeing to more rigorous inspections by the IAEA to [demonstrate] the peaceful nature of its nuclear program."
In addition, he told the Monitor that Iran's avowed willingness to stop 20 percent enrichment if the US shows goodwill underscores that nuclear talks need not be a zero-sum game in which only one country benefits.
"The nature of Iran's nuclear program is such that it directs Iran and the United States to either interact or engage in war," he says. "In other words, it is either a win-win game or a lose-lose game, and not a win-lose game."