DUBAI — 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 Rohani 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 US 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 counter-parties 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. "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. Cup of poison 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 UN 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. — Reuters