After years of failure, Iran and the six world powers may finally make some progress on nuclear negotiations when they meet again Saturday if each side shows willingness to offer concessions the other seeks.
But even if the two sides find enough common ground, they may have a tougher time in any potential second round. That's when the six powers will likely seek further commitments from Tehran to reduce fears that it could use its uranium enrichment program to make the fissile core of nuclear missiles.
Iran has proposed Baghdad as a possible venue for any follow-up meeting, and a European diplomat said Friday the six could agree to meet there in May if there were enough progress in Istanbul. Like several officials and diplomats interviewed by The Associated Press, he demanded anonymity because he was not authorized to publicly reveal confidential information.
As it comes to the table in Istanbul, the West's strongest hand is linked to its sanctions on Iran, penalties that have been tightened in recent months as the U.S. and EU have taken aim at Iran's main cash cow: oil. Tehran in turn, may dangle the prospect of halting high-level uranium enrichment, a process that would shorten the path to making warhead material should it opt for that route.
Diplomats from some of the six powers _ the United States, Russia, China, Britain, France and Germany _ said rolling back existing sanctions would be premature and too much of a reward if Iran offers no more than discussions about stopping its enrichment of uranium to 20 percent.
But other sanctions are still unfolding. U.S. moves to punish any bank, company or government that does business with Iran's central bank, its main conduit of oil trade, are to take full effect June 28, just three days before a full oil embargo from the European Union kicks in.
The European diplomat said it was unlikely Western powers would use the talks to offer the possibility of putting the oil penalties on hold if Tehran shows readiness to compromise on 20-percent enrichment and other demands. But the U.S. and the E.U. would be free to review them independently outside of the talks framework and suspend new penalties now in the works if the dialogue showed signs of progress.
Officially, the international community's long-term goal remains what it was when nuclear negotiations began eight years ago _ persuading Tehran to stop all uranium enrichment and thereby relieve fears that it will use that program to create the fissile core of nuclear warheads. Tehran has long denied any weapons-related nuclear goals.
A diplomat involved in the talks said, however, that influential Western nations are coming around to the idea that Iran should be allowed to keep some enrichment activity "under the right circumstances," sometime in the future, if fears about possible weapons plans are put to rest.
U.S. Secretary of State Hillary Clinton challenged Iran to prove its intentions are peaceful, saying Thursday: "We want them to demonstrate clearly in the actions they propose that they have truly abandoned any nuclear weapons ambition."
In Tehran, Heshmatollah Falahatpisheh, head of the parliamentary committee on foreign relations, said the talks in Istanbul will be "hard and heavy." In a telephone interview, he reiterated Iran will not step back from its nuclear activities.
Still, officials from some of the countries that will be at the table with Iran say that even a sign from Tehran that it is ready to lift its taboo on talking about enrichment may be enough for more talks that will attempt to focus on specifics.
Iranian officials have suggested scaling back on uranium enrichment while continuing to make nuclear fuel and ahead of the talks, chief Iranian nuclear negotiator Saeed Jalili vowed to present new initiatives, without specifying what they might be.
Iranian Foreign Minister Ali Akbar Salehi sounded a conciliatory tone in a Washington Post opinion piece.
"A house can burn to the ground in minutes but takes a long time to build. Similarly, trust can easily and rapidly be broken, but it takes a long time to build," he wrote, adding his hope was that "all sides make genuine efforts to re-establish confidence and trust" at the talks.
Washington has warned that Saturday's meeting may be the last chance to try to persuade Iran to curtail enrichment at the negotiating table. The other option _ a military strike by Israel _ would risk drawing in the United States, for Washington a horror scenario even if were not an election year.
An official on one of the Western delegations described the six as an "extraordinarily unified group" on the matter at hand. That view was echoed by chief Russian negotiator Sergei Rybakov, who said the only difference with the West was whether sanctions were helping or hurting attempts to engage Iran.
Russia and China are strategic and economic partners of Iran that have acted as a past brake on harsh sanctions, but a diplomat involved in the talks said they have had "significant influence" on the Iranians in nudging them toward a more conciliatory position.
Rybakov and senior Chinese negotiators met separately Friday with senior Iranian negotiator Ali Bagheri and came back with the message that Saturday's session is "not going to be easy," a diplomat said.
Another diplomat familiar with the talks said Iran conveyed through the Russians and the Chinese that it was interested in setting up a "roadmap" for future talks. But that term has negative connotations for diplomats trying to engage Iran.
Talks between the International Atomic Energy Agency meant to focus on allegations that Tehran was hiding nuclear weapons-related experiments foundered after months of back and forth that focused on a "roadmap" on how those investigations would proceed instead of the substance of what should be investigated. The agency has made no progress on that issue for more than three years.
Since 2002, Iran has weathered growing economic and political penalties to turn an experimental program into uranium enrichment that harnesses more than 9,000 machines. It moved last year from turning out just nuclear fuel grade material to additional higher-level enrichment at 20 percent that would allow it to make weapons-grade uranium more easily and quickly.
Adding to concerns, it has moved that higher-level operation into a mountainside bunker that may be safe from even the biggest bunker busting bombs.
George Jahn can be reached at http://twitter.com/georgejahn
Associated Press writers Nasser Karimi and Suzan Fraser in Istanbul, Juergen Baetz in Berlin and Mark S. Smith in Washington contributed to this report.