The tentative agreement reached in Vienna on Wednesday to substantially reduce Iran's stockpile of low-enriched uranium raises a tantalizing question: After 30 years of hostility, could this be the beginning of a thaw in US-Iranian relations?
No one paints the deal as a Nixon-to-China watershed moment that from now on puts relations on positive and constructive footing. But it could nonetheless be the beginning of a shift from a dominant antagonism to an openness to addressing mutual interests, some diplomatic experts say.
"Let's definitely have modest expectations here. There's a lot for the two countries to get through as they consider taking this dialogue further," says Trita Parsi, president of the National Iranian American Council in Washington. "It's going to take much more for any tentative openness to take hold, but this could prove to be the first step in turning the trajectory of US-Iranian relations."
The Vienna agreement, reached tentatively among Iranian, American, French, and Russian negotiators under the auspices of the International Atomic Energy Agency (IAEA), calls for much of Iran's low-enriched uranium (LEU) stockpile to be shipped outside the country for reprocessing.
The reprocessed uranium would then return in a form essential to operation of a Tehran research reactor. But it would be well below enrichment levels required for a nuclear weapon.
Iranian negotiators were to take the accord back to Tehran for final approval, possibly by Friday.
By cutting Iran's stock of LEU by about three-fourths, the deal would give world powers as much as a year of breathing room for addressing the broader challenges of Iran's nuclear program.
That period of reduced tensions over Iran's nuclear program will be crucial to both the United States and Iran as they gauge how far a tentative thaw in relations can go, Mr. Parsi says.
"Much has been made of how this deal would allow a testing time for the US and its partners to measure Iran's intentions without the nuclear program breathing so heavily down their necks. But the Iranians see it as a test as well," he says. "From their perspective, they've done things in the past aimed at building confidence on the American side, but they feel it hasn't been appreciated."
In assessing the talks, IAEA head Mohamed ElBaradei alluded to a conscious effort by all parties to keep in mind the potential for this one accord to begin reversing longstanding disputes.
"I must say that everybody who participated at the meeting was trying to help, trying to look to the future and not to the past, trying to heal the wounds that existed for many, many years," Mr. ElBaradei told journalists.
Other security experts, especially those convinced that Tehran's larger ambitions continue to include a nuclear weapon, caution against reading too much into one action – and a tentative one at that.
"To my way of thinking, they've taken a page from the North Korean playbook," says Gary Schmitt, director of advanced strategic studies at the American Enterprise Institute in Washington. "They sense there are some advantages to looking like they are cooperative and to in fact being cooperative."
The Iranians "may not be ready" for a number of reasons to move ahead on their nuclear ambitions, Mr. Schmitt says. And, he suspects, they may welcome their own "breather" from international pressures to focus more on domestic concerns – specifically, the ramifications of the summer's disputed presidential elections.
He cautions against assuming that even a signed agreement means that the Iranians have decided on a clear path forward.
"It's especially difficult to get a handle on how the Iranian leadership thinks," he says. Noting that his contacts with Iran go back to the 1980s, he says, "You can never assume you've got the straight answer, and they always put eight faces on the same problem."
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