NEW YORK – Among the arguments Iranian officials are marshalling in the nuclear negotiations that resumed this week in New York is that domestic politics severely constrain their ability to compromise.

This is the best we can do, they seem to be saying: Accept our position or you will face even more hardline interlocutors in the future.

Addressing the Council on Foreign Relations Wednesday evening in New York, Iranian Foreign Minister Javad Zarif reminded the elite audience what happened in 2005 when the George W. Bush administration rejected a prior Iranian nuclear offer: Mahmoud Ahmadinejad was elected president, Iran accelerated its nuclear program and Zarif, a pragmatic former UN ambassador, was forced into “early retirement.”

Eight years later, Zarif was reinstated and promoted by Iran’s new president Hassan Rouhani.

“Now that I’m back from the dead,” Zarif quipped, “it’s important for us to be careful about the type of messages the international community is sending to Iran.”

Under Iran’s bifurcated political system, a cleric — Ayatollah Ali Khamenei — has the final word on all key foreign and domestic decisions. Supreme Leader Khamenei laid out parameters that seem to require a large expansion of Iran’s uranium enrichment program before 2021 when a current agreement with Russia to provide fuel for Iran’s sole nuclear power plant at Bushehr expires.

Khamenei’s red lines may also be reflected in Iranian refusal so far to reduce the number of centrifuges they currently operate — about 10,000 — and Tehran’s demand that the duration of any restrictions on the program be relatively short.

“We have to establish confidence,” Zarif said on Wednesday. “If you cannot establish confidence in five years … then the agreement is meaningless.”

Zarif pointed out that it is not just Americans who are suspicious of Iranians but vice versa. “Don’t ask us to put all our faith in promises while you’re not prepared to accept our promises,” he said.

U.S. negotiators also appear to have boxed themselves in by insisting on a significant initial reduction in centrifuges and an agreement that lasts for at least a decade.

Speaking in Washington Tuesday, Undersecretary of State for Political Affairs Wendy Sherman, the principal U.S. negotiator with Iran, said, “I fully expect in the days ahead that Iran will try to convince the world that on this pivotal matter, the status quo — or its equivalent — should be acceptable. It is not.”

A senior Obama administration official, speaking on condition of anonymity Thursday evening, was slightly more upbeat. The official described initial bilateral talks with the Iranians in New York as “constructive,” adding that “it is clear that everyone has come here to go to work.”

Still, the extent of the gaps between positions on key issues has generated pessimism about the prospects for agreement over the next ten days when the world’s leaders descend on New York for the annual summit of the UN General Assembly.

The mood this year is even more somber because of multiple other crises, from the Ebola epidemic in Africa to the bloodshed in eastern Ukraine and the rise of the terrorist group that calls itself the Islamic State (IS) group.

Proponents of a nuclear deal with Iran argue that it is a prerequisite for U.S.-Iran collaboration on other urgent regional problems.

“Those in Iran who want to pursue a dialog [on other issues] don’t have the power to do so without a nuclear agreement,” Thomas Pickering, a former undersecretary of State for political affairs and veteran ambassador, said Thursday at a meeting in New York sponsored by The Iran Project, a bipartisan group largely comprised of former senior U.S. officials.

A new report from the group — endorsed by other former State Department heavyweights including Ryan Crocker and former national security advisers Zbigniew Brzezinski and Brent Scowcroft — argues that “a comprehensive agreement on Iran’s nuclear program will be a catalyst for change in the ever-turbulent Middle East [that] may involve new forms of cooperation … with unusual bedfellows.”

“There is a strong link between settling the nuclear standoff and America’s ability to play an effective role in a rapidly changing Middle East, and that a nuclear agreement will help unlock the door to new options,” the report adds.

Iranian officials have rejected overtures for overt collaboration against IS, although tacit understandings appear to have been reached in Iraq, where both the U.S. and Iran support the Baghdad government and Kurdish authorities. Syria, where the U.S. opposes both the IS militants and the government of Bashar al-Assad, is more problematic.

Frank Wisner, a member of The Iran Project and former U.S. ambassador to Egypt and India, said Iranian participation in a “Geneva III” process was essential to find a political solution to the Syrian civil war, which helped give rise to IS. “The most significant source of influence in Syria is Iran,” he said. Iran would be prepared to discuss a political transition in Syria that did not require the removal of Assad as a prerequisite, Wisner added.

Without a nuclear deal, however, the chances for U.S.-Iran collaboration on any other issue will be slim and elements in Iran that historically have distrusted the U.S. will be empowered, the experts said.

Already, the Rouhani government is facing pushback from some members of the Revolutionary Guards, the judiciary and the parliament, which — in a mirror image of critiques of Obama by some Republican hawks — argue that Zarif and company have already conceded too much.

Without a deal by Nov. 24, the current deadline, Rouhani — who campaigned on a promise to get nuclear-related sanctions lifted — would be weakened further. More ideologically rigid politicians would likely win upcoming elections for the body that nominally supervises the Supreme Leader — and picks his successor when he dies — and for the Iranian parliament in 2016.

Zarif, perhaps Iran’s most adroit and articulate spokesman, of course is partly spinning when he warns of dire consequences if the U.S. rejects compromise. But there is an element of truth to his arguments and the history of Iran shows that officials who unsuccessfully attempt rapprochement with the West are quickly marginalized — or worse.

Given the history of missed opportunities and misunderstandings on both sides during three decades of estrangement, it would be prudent for U.S. officials to give some consideration to the possible political fallout in Iran and the implications for the wider Middle East if these nuclear negotiations fail.

Barbara Slavin is a senior fellow at the Atlantic Council’s South Asia Center and a correspondent for Al-Monitor.com, a website specializing in the Middle East. She is the author of a 2007 book, Bitter Friends, Bosom Enemies: Iran, the US and the Twisted Path to Confrontation, and is a regular commentator on U.S. foreign policy and Iran on NPR, PBS, C-SPAN and the Voice of America.

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