Iran's assertion that it has the right to enrich uranium for peaceful purposes is expected to be a key focus of high-level international negotiations on Iran's nuclear program that resume this week.
Iran's claim was the primary reason for the talks adjourning without an interim agreement on Nov. 10, with the United States spurning wording that would grant an automatic right to enrichment, the process by which uranium is turned into fuel for power-generating reactors and nuclear warheads alike, according to experts familiar with the issue. Yet U.S. officials also know the negotiations will collapse if they demand a complete halt to Iran's program, which they fear is intended to produce a weapons-building capability and which Iran insists is for peaceful purposes only.
A major question, then, as the talks restart Wednesday in Geneva, is whether the United States, Russia, China, Britain, France and Germany – known as the P5-plus-1 – and Iran can craft language that is loose enough to accommodate all views on the issue but strict enough to hold Tehran to firm enrichment limits.
"You can go down a rabbit's hole in all sorts of different ways on this," explained Daryl Kimball, executive director of the Arms Control Association, a policy institute. "But in the end, these negotiations will have to settle whether Iran can continue the enrichment of uranium to some extent."
Settling Iran's claim to the right to enrich uranium for peaceful uses is crucial to the final outcome of what many officials and experts see as the best chance in a decade to settle the feud in which the United States and Israel have threatened military action to prevent Tehran from building nuclear arms.
"Good progress made in recent negotiations, but they have to note, resorting to excesses could complicate our journey to a win-win outcome," Iranian President Hassan Rouhani wrote on his official Twitter account Monday.
Enrichment can produce different uranium purity levels, depending on how long the process runs. Low levels of purity can be used for power reactors and medical uses, while nuclear weapons require uranium that is highly enriched to 90 percent purity.
Iran insists it is only interested in peaceful programs, but there are a number of reasons the United States and other nations remain suspicious. For one, its stockpile of enriched uranium includes about 440 pounds of uranium enriched to about 20 percent purity, far more than is necessary for the research reactors that would make use of that fuel.
Additionally, the history of the program is concerning. Iran started its program with technology purchased from an international smuggling ring led by the father of Pakistan's nuclear weapons, and the U.N. International Atomic Energy Agency says it has evidence that Iran secretly researched a missile-borne nuclear warhead until late 2003.
U.S. and European officials worry that Iran is putting in place the capability to quickly produce a bomb should it ever decide to do so.
U.S. and European officials have said that a preliminary deal that would prevent such a scenario was within reach when the talks collapsed last month.
Rouhani, a pragmatic cleric who unexpectedly prevailed in June elections partly on a pledge to end crippling international sanctions imposed on Iran for defying U.N. orders to halt its program, has much at stake in defending the Iranian claim to an enrichment right.
For now, Rouhani is backed in the negotiations by Iran's supreme leader, Ayatollah Ali Khamenei. But he'd suffer a potential crippling backlash if his government relinquished its claim that it has the right to enrich uranium. The country has spent billions developing an enrichment capability and thousands of scientists are employed in the program.
"It's a point of ideological importance to the Iranian regime because this is what the regime has been fighting for for the past decade," said Alireza Nader, an Iran expert with the RAND Corp., a policy institute. "It has based its struggle with the international community on this right to enrich uranium."
To the United States and other powers, Iran's signature on the Non-Proliferation Treaty – the keystone of the global system to halt the spread of nuclear weapons – doesn't confer an automatic enrichment right. That's especially so because Tehran hid its program from U.N. inspections for 18 years and still is refusing to disclose the full extent of its research.
Tariq Rauf, a former senior IAEA official, pointed to the way that European Union negotiators approached the question in 2004 as a possible solution to Iran's claim to an enrichment right.
The EU, he said, acknowledged Iran's inalienable right under the Non-Proliferation Treaty to use nuclear technology for peaceful purposes, but only as long as it conformed to provisions in the accord barring the development of nuclear weapons.
The issue holds significant political risks for President Barack Obama. Israel and Saudi Arabia, key U.S. regional allies, don't trust Iran and are alarmed over the prospect of a U.S.-Iranian rapprochement. Some Democratic and Republican lawmakers, encouraged by intense pro-Israel lobbying, are moving to stiffen sanctions against Iran – a move that Obama has warned could undermine the Geneva talks.
Obama was expected to reiterate that theme in a meeting Tuesday with Democratic and Republican leaders of key Senate committees, White House spokesman Jay Carney said Monday.
"When it comes to our position on additional sanctions, I'm sure that this will be a topic because it's the president's view that it's the right thing for Congress to . . . pause so that we can test whether or not the Iranians are serious about resolving this issue diplomatically," Carney said.
The draft accord to be presented to Iran in Geneva this week would set limits on what Iran could do with its enrichment capabilities.
According to experts familiar with the issue, Iran would have to halt its production of near 20 percent enriched uranium, which requires little further purification for use in a warhead. Its stockpile of 20 percent uranium would be disposed of, either through dilution or by conversion into fuel for a research reactor used to make medical isotopes.
Iran would agree not to turn on additional centrifuges, the high-speed spinning machines in which uranium is enriched, said the experts, who requested anonymity because of the delicacy of the diplomacy. Iran now operates some 10,000 of some 19,000 first-generation machines, called IR-1s, installed at two sites. Advanced machines, known as IR-2Ms, couldn't be activated, either.
Iran could not fuel its Arak heavy water reactor, preventing it from activating the facility that would give it another avenue to a nuclear weapon through the production of plutonium, they said.
Moreover, it would have to submit to more frequent and extensive IAEA inspections of its uranium enrichment plants at Natanz and Fordow, the experts said.
In return, Iran would be given access to about $3 billion of some $50 billion in assets frozen under international sanctions. At the same time, another $15 billion to $20 billion in assets would be frozen under existing measures.
Some limits would be waived on Iran's trade in petrochemicals, gold and other precious metals, international measures against its automobile and aircraft industries would be lifted and access to humanitarian aid would be made easier, they said.
Roy Gutman in Istanbul and Lesley Clark in Washington contributed.
By Jonathan S. Landay
McClatchy Washington Bureau