DUBAI, (Reuters) - For a man with the title of Supreme Leader, Iran's Ayatollah Ali Khamenei has been noticeably unwilling to claim the credit for a nuclear deal that marks a turning point in the history of the Islamic Republic.
In the month since Iran reached an accord with world powers to limit its nuclear program in exchange for sanctions relief, Khamenei has called for public debate and refrained from making decisive statements.
He has been silent on whether he himself backs the accord.
At first sight it appears a curiously reticent stance for the man who wields ultimate power in Iran and gave political cover to President Hassan Rouhani in 2013 to pursue talks with world powers including Tehran's old enemy, the United States.
Now a deal has been done, many see the chance of the leadership eventually rejecting it as small, since Tehran needs the removal of sanctions to revive its economy.
But powerful factions in Iran still dislike the agreement, and there is no guarantee it will succeed. The complex deal could also be derailed by a combative U.S. Congress or fall apart at some point down the road.
Should that happen, anyone who supported compromise with the West could face a career-ending backlash inside Iran.
The deal is meant to last for many years: So Khamenei's reticence is a means to shield himself in case it collapses one day, something that could happen if Iran or its counterparties determine the terms have been breached, political experts say.
"Ayatollah Khamenei's silence is calculated. He is weighing up the situation," Isa Saharkhiz, former deputy Minister of Culture, said by phone from Tehran.
"He is standing cautiously somewhere in the middle, so no one can interpret his words as approval or disapproval."
This way he can stay above the internal rivalries of Iran's unwieldy dual system of clerical and republican rule, in which factions are seeking to gain maximum benefit from the deal while taking the least responsibility.
Khamenei became supreme leader in 1989 after the death of Ayatollah Ruhollah Khomeini, who led the revolution to overthrow the pro-Western Shah 10 years earlier. Despite lacking Khomeini's revolutionary authority and charisma, Khamenei has held on to power for 25 years by deftly balancing the interests of numerous factions.
“There is no doubt that nuclear negotiations started when Khamenei gave the green light and he was regularly briefed on all the details," Saharkhiz said.
"But Khamenei has supporters inside Iran and outside who are asking what will happen to the Islamic Republic’s anti-American policies. This hampers Khamenei’s ability to maneuver."
The 76-year-old cleric still refers to the Joint Comprehensive Plan of Action as a "text" rather than a deal, and has asked experts to analyze it and share their opinions.
In a letter to Rouhani published on Khamenei's website, the Supreme Leader wrote: "The successful end of the nuclear negotiations is a significant step, but the text should be carefully scrutinized and the legal procedures should be taken so when it is ratified the other side cannot breach it."
Increased censorship in the media of voices critical of the accord, however, suggests that not all opinions are equally welcome in Iran's tightly controlled public domain, over which the Supreme Leader has final oversight.
And it is not clear exactly how the deal will be approved in Iran or what role parliament and the Supreme National Security Council will play, a sign both of the opaque workings of the Islamic Republic and the momentous nature of the deal.
"The critics of the nuclear deal have financial and even military power. Ayatollah Khamenei has no choice but caution in the face of a deal that changes the future of Iran," said Kourosh Zaim, a leading member of the opposition National Front movement.
Parliamentary speaker Ali Larijani last week compared the deal to the end of Iran's eight-year war with Iraq, noting that United Nations Security Council Resolution 598, which ended the war had "completely transformed the situation in Iran".
"We are now in a transition period again after the nuclear deal, moving to a new stage after a 12-year challenge," Larijani was quoted as saying by state broadcaster IRIB.
It has not gone unnoticed in Iran, a nation with a keen sense of history, that the U.N. Resolution endorsing the nuclear deal was adopted on July 20, the anniversary of Iran's adoption of Resolution 598 in 1988.
Khomeini, the first Supreme Leader, took full responsibility for making peace with Iraq, comparing the decision to drinking a cup of poison.
While parliament was not involved in ratifying the peace deal with Iraq, Khamenei, in contrast, has allowed lawmakers to debate the nuclear deal. They have summoned nuclear negotiators and grilled them on the technical aspects of the deal.
This sharing of accountability for the deal appears astute, given that not even Khamenei can match the prestige and power of the country's revolutionary leader, experts say.
"Ayatollah Khomeini was a powerful leader and no one dared to disagree with his decisions. But Khamenei's position is not the same," Zaim said.
Reporting by Bozorgmehr Sharafedin; Editing by Sam Wilkin, William Maclean and Giles Elgood