After Secretary of State John F. Kerry sits down Thursday with his Iranian counterpart to start the highest level talks between the two nations in 34 years, negotiators for the two sides are likely to grapple with a highly sensitive issue:
Can the mullahs in Tehran be trusted to enrich uranium — potential nuclear bomb fuel — to even low levels on their own soil?
President Obama and newly elected Iranian President Hassan Rouhani both implicitly raised the question during their addresses Tuesday to world leaders at the annual United Nations General Assembly gathering. It doubtless will come up again Thursday when Kerry meets with Iranian Foreign Minister Mohammad Javad Zarif.
Rouhani, a relative moderate who has vowed to thaw relations with the West, referred to Iran's "sovereign right" to enrich uranium for power plants and other nonmilitary uses.
Obama was more guarded, saying America respects the "right of the Iranian people to access peaceful nuclear energy."
Some analysts noted the similar language and speculated that the two governments used back-channel talks to consider a possible route to a deal that would force Iran to give up any bomb-making capabilities but would allow low-level enrichment closely monitored by U.N. nuclear inspectors, just as happens in other countries under the Nuclear Nonproliferation Treaty, which Iran has signed.
The president has not approved an enrichment deal for Iran, but some analysts believe he used his speech to float a diplomatic trial balloon.
The Obama administration, like the George W. Bush administration, has never publicly affirmed Iran's right to enrich uranium. But as Iran has steadily moved closer to bomb-making capability, and Washington and its allies have sought to stop the process short of going to war, the question has gained urgency.
To advocates, including some current and former Obama administration officials, and some foreign governments, allowing Iran to enrich uranium for energy may be a face-saving way to curtail Iran's broader nuclear ambitions. The West suspects that Iran ultimately aims to build a nuclear weapon, a goal Iran has repeatedly denied.
To skeptics, including the Israeli government and many in Congress, even enrichment of uranium to 5% purity — the level used for civil power plants — would amount to surrender. Iran, they believe, would require the West to ease punitive economic sanctions as part of any deal, and secretly move nuclear work into hidden sites until it reaches bomb-making capability.
"This is not the time to concede domestic enrichment or plutonium reprocessing to the Iranian regime, just because it demands that this is nonnegotiable," said Mark Dubowitz of the pro-sanctions Foundation for Defense of Democracies.
Dubowitz said he believes that Obama's U.N. speech "left open the door" for domestic enrichment in Iran. He called that prospect a potential catastrophic mistake given Iran's history of hiding enrichment facilities, destroying evidence and refusing to provide full access to inspectors from the International Atomic Energy Agency, the U.N.'s nuclear watchdog.