In a nation riven by political fault lines, no issue resonates with as much public support and national pride as the pursuit of nuclear technology.
So as Iranians prepare to vote for a new president on Friday, front-runner Ali Akbar Hashemi Rafsanjani is seeking to reassure Iranians and the West alike that Iran's intentions are peaceful.
"No, we will never give up this quest [for the nuclear-fuel cycle]," Mr. Rafsanjani said late Saturday. "But we will create the necessary trust that this is for peaceful purposes. I'm seriously convinced that this will be solved."
Iran has been cited by the UN's nuclear watchdog for a string of reporting violations that stretch back two decades.
The International Atomic Energy Agency (IAEA) board of governors is due to hear an oral report on the Iranian case this week in Vienna. Monday, Mohamed ElBaradei was reappointed for a third term as the agency's head after the US dropped its lone effort to unseat him.
Reports indicate that the US is hoping for a tougher IAEA stance, though mixed signals have emerged in the past week.
Diplomats say that initial results of IAEA tests on traces of bomb-grade uranium, found two years ago on centrifuge parts purchased from Pakistan, are identical to those on parts provided by Pakistan last month - apparently confirming a longstanding Iranian explanation that Tehran did not produce the material itself.
A Western diplomat close to the IAEA investigation in Vienna said results still needed to be verified and peer-reviewed before a final determination.
Also, IAEA inspectors confirmed last Thursday that Iran had followed through with promises to suspend sensitive work at an underground uranium-enrichment facility at Natanz.
Separately, however, the Iran Defence News, which tracks Iranian military developments, reported Monday that Iran is negotiating with a North Korean team in Tehran that includes "specialists in underground construction who helped to design the bunkers that contain Pyongyang's [nuclear] weapons program."
The report quotes unnamed Western intelligence sources saying the proposal for a 10,000-square-meter underground facility could hide a weapons project.
Iran denies that it has ambitions to build a nuclear weapon, and has chafed at an 18-month suspension of enrichment activities it says are meant to produce nuclear fuel for power, not bombs. Iran's parliament, controlled by hard-line factions for more than a year, recently passed legislation obliging the government to pursue enrichment.
Iran has made no promises beyond July, when negotiators from Britain, France, and Germany - in a long-running diplomatic effort - are to detail a list of incentives.
"There is breathing space, but still an intractable problem," says a Western diplomat, about the roller-coaster EU-Iran talks.
The European negotiators, with indirect support from the US, insist that Iran permanently halt enrichment.
Iran counters that, as a signatory of the nuclear Non-Proliferation Treaty (NPT), it is allowed peaceful pursuit of nuclear technology, and should not be forced to stop.
"People are putting way too much faith that Rafsanjani can come in and solve it," says the diplomat, who asked not to be named. "The truth is, he is one of the fathers of Iran's nuclear program, and he is not known for making easy deals. Lebanon hostage negotiations [in the 1980s] dragged on for years."
Already, Iranian officials have promised their nation that it will be a nuclear power, in a neighborhood that includes the nuclear-weapon states of Israel, Pakistan, and India.
"It's become a point of national pride - even if the politicians want to reverse, it's too late," says Shirzad Bozorgmehr, deputy editor of the English-language Iran News. "People get insulted when the US says, 'You are not trustworthy to have nuclear technology.' Who are you? They feel oppressed on this issue."
Despite criticism from Washington that the EU-Iran talks permit more time for any clandestine work, analysts say the 18-month suspension has brought a new "stability" to the issue.
Proposals floated now include recognizing Iran's right to nuclear technology, while essentially putting the program on hold for five or 10 years.
But is such a compromise acceptable to Iran? "Definitely not," says Hussein Shariatmadari, a representative of Iran's supreme religious leader, and editor of the fundamentalist Kayhan newspaper. "We are very clear in this regard, and very legal."
"Whatever is going to happen after five years of suspension, is going to happen now," says Mr. Shariatmadari, adding that right-wing factions prefer that Iran pull out of the NPT altogether. "The only difference is we lose the benefit, put down our machines, and our technicians and scientists are out of work. In the long run, suspension means it's stopped."
Which could still be possible, some argue, if the price is right.
"I believe there will be an [EU-Iran] agreement, if you give [Iran] a big piece of the cake," says analyst Saeed Laylaz, ticking the removal of sanctions, WTO membership, and perhaps a $20-$30 billion loan for "shopping" in Western markets.
Iran would keep a token 500 centrifuges for limited enrichment, he suggests, which could be used as political cover for the regime. The US would have to join the negotiations, but could use the NPT framework as a "good umbrella" to talk directly to Iran. Rafsanjani was due to meet Monday with the ambassador of Switzerland, which handles US interests in Iran.
"If the US makes a big step toward negotiations, directly after a Rafsanjani win, you can go ahead very fast with a good proposal," says Mr. Laylaz. Iranian negotiators have been "looking for a gap between the EU and the US; Rafsanjani is looking for an agreement. We need it."