Iranian president Hassan Rouhani’s overtures to the United States last week might prove the first chapter in an American-Iranian détente which could benefit the interests of both nations — if possibly at the expense of America’s relations with Arab powers.

Hours before leaving for New York on Sunday to address the General Assembly of the United Nations there, Rouhani, who was surprisingly elected president in June when he was relatively the most moderate candidate in the race, reiterated that he was prepared to restart negotiations with the West over his country’s nuclear program — provided it set no preconditions and recognized Iran’s right to enrich uranium for peaceful purposes.

In an interview with the American news channel NBC that was broadcast on Thursday, Rouhani vowed that Iran would never “seek weapons of mass destruction, including nuclear weapons” and insisted that he had “full power and complete authority” to do a deal, allaying fears that the Islamic country’s supreme political and religious leader Ali Khamenei might thwart an accord.

In evidence that Rouhani is able to exercise his authority over the matter, he switched control of the nuclear issue from the hawkish national-security council to the Foreign Ministry which is now led by Mohammad Javad Zarif, a veteran of American-Iranian diplomacy.

Iran’s charm offensive has been met with cautious optimism in the United States. President Barack Obama sent Rouhani a letter congratulating him on his victory three months ago while a White House spokesman last week suggested the two leaders could meet on the sidelines of the General Assembly in New York.

America’s special representative for Afghanistan and Pakistan, James F. Dobbins, was even more hopeful, telling the Inter Press Service last week that if the countries were able to overcome their differences, “I do see opportunities for dialogue and cooperation on a broader range of issues, including my issues, which is to say Afghanistan.”

Neither America nor Shia Iran wants to see the Sunni extremist Taliban return to power in Kabul. Nor does nearby India which seeks to strengthen its security ties with the United States in order to balance against China’s rise in Asia but which is also dependent on Iranian oil and gas exports. American-Iranian discord thus prevents a great power settlement in Afghanistan as well as deeper American-Indian relations.

American concerns about Iran’s nuclear program largely stem from the country’s own violent extremism. Iran arms and finances terrorist groups, notably Lebanon’s Hezbollah which now fights on the side of Syrian president Bashar Assad’s army in a civil war that pits the Levant country’s minority Alawite regime against the majority Sunni population.

The sectarian divide runs across the region with the United States backing both Sunni Turkey and Sunni monarchies in the Persian Gulf. An accommodation with Iran would alarm especially the latter. Saudi Arabia is locked in a fierce struggle for regional hegemony with Iran and has hinted that it might seek a nuclear weapons capacity of its own if Iran attains one.

It might nevertheless be in the United States’ interest to pivot on the Shia-Sunni divide, argued Greg R. Lawson at the Atlantic Sentinel last year. While it could exacerbate tensions and foment unrest in the short term, “the United States have no reason to desire a particularly stable Middle East. Most oil from the region goes to Europe and Asia, not America,” he pointed out.

While instability will roil the markets, this may, paradoxically, give the United States more incentive to continue taking advantage of its still copious amounts of domestic natural resources not for national “self-sufficiency” but to become a pivot exporter along with Russia.

Russia, indeed, might be persuaded that it stands to benefit from such a scenario. It could continue selling arms to Syria and help advance Iran’s nuclear energy program without the United States hectoring it on its close ties to unpleasant regimes. “This may set the stage for a far more productive relationship on other issues than the much ballyhooed ‘reset’ ever did.”

Yet American-Russian relations are not the main component of Lawson’s strategy which is designed to prevent the United States from being continuously sucked into the endless sandstorms of the Middle East.

Today, the United States is stuck trying to contain Iran without the military flexibility to be serious, thus looking a bit like a paper tiger. Tomorrow, it could seize the geopolitical initiative by being the decisive weight on the scale of Sunni-Shia relations. Both would be forced to cultivate relations with the United States in order to maintain its support.

The private intelligence company Stratfor’s Robert D. Kaplan and Kamran Bokhari similarly argued in May that the America should pursue détente with Iran for its long-term security, if only because the country is far more stable than its current partner Saudi Arabia — “built around the parched and deeply conservative upland of Najd which has always struggled to subdue the more cosmopolitan maritime peripheries like Hijaz.” Iran, by contrast, is a coherent geographical entity that “straddles the Middle East and Central Asia as well as the two energy producing regions of the Persian Gulf and the Caspian Sea.”

Rather than an artificial contrivance of a single family, Shiite Iran — with its relative geographic logic — is heir to Iranian states going back to antiquity, when Persia was the world’s first superpower. Iran encapsulates a rich and eclectic civilization. Even under the present regime, in Iran there is a semblance of a democratic foundation, while in Saudi Arabia there is an utter lack of any sense of democracy.

A rearrangement of America’s alliances in the Middle East would surely take time and might not have to require abandoning Sunni friends. Turkey is, after all, a NATO ally while Saudi Arabia is in the process of acquiring $60 billion worth of American aircraft and other military equipment. Recent diplomatic advances are also a far cry from the close relations the countries maintained under the last Iranian shah. But Arab Gulf states’ inherent regime instability and the United States’ partisan allegiances in the Middle East’s sectarian conflicts, which make it vulnerable to power shifts, suggest it could do better with Iran than contain it.