Despite these doubts, it is worth noting that during the 10-year period of failed negotiation dating from 2003, when President George W. Bush torpedoed his own diplomats' efforts at rapprochement by carelessly declaring Tehran to be part of an "axis of evil," Iran has gone from running 164 centrifuges at a single pilot plant to some 19,000. The international sanctions by themselves, no matter how harsh they have grown, were not enough to stop that progress, only to bring Tehran tentatively to the table. The pact will, for the first time, halt that aggressive building program and, just as importantly, perhaps shore up the political position of the Iranian moderates who were silenced for most of that decade.
If the United States and Iran can build on this potential rapprochement, it "will likely redraw the geostrategic architecture in the Gulf and the Middle East," says Gerges. A lot could become possible that was not before. In Syria, Bashar al-Assad is gaining ground and refusing to talk to the rebels largely because of the help he's getting from Iran-backed Hezbollah troops. In increasingly violence-wracked Iraq, Shiite Prime Minister Nuri al-Maliki feels he has a freer hand to sideline Sunnis (thereby giving new life to al-Qaeda in Iraq) because of support from Tehran, to which Maliki is also granting overflight rights for weapons supplies into Syria. If post-2014 Afghanistan is to gain any stability, Iran must be induced to resume its formerly hostile relationship with the Sunni Taliban in the West. And if Iran can be persuaded to further distance itself from Hamas (Tehran reportedly slashed funding in anger after Hamas moved its headquarters from Damascus to Qatar) and at least quiet its anti-Israel rhetoric, that would make a Palestinian peace deal more possible.
For Obama, the domestic politics are perilous, of course, just as they were in 1972 for Nixon, who had to face harsh recriminations from his former fellow anti-communist colleagues on Capitol Hill and the powerful anti-détente lobby. Yet Nixon too saw the need to break through a geopolitical situation that was frozen in place for more than a decade. "In Asia, the United States was stuck with a China policy that obliged it to act as though Chiang [Kai-shek] and the other losers of the Chinese civil war were someday going to retake the mainland. The United States was enmeshed in a war in Vietnam that was costing up to 15,000 lives a year," James Mann wrote in his 1999 book About Face. "Nixon's initiative was aimed at breaking all of these shackles and creating a world in which American foreign policy would have greater flexibility."
In the end, the latest attempt could come down to whether Obama and Secretary of State John Kerry can create a kind of cold peace in the region—a verifiable if informal mutual reassurance pact between Iran, Israel, and Saudi Arabia. Israel needs to be reassured that Iran is not hell-bent on destroying it with a nuclear bomb; and Saudi Arabia that it doesn't need start up its own nuclear weapons program to counter Tehran's. But the hardest sell of all may be left to Iranian President Hassan Rouhani and Foreign Minister Mohammed Javad Zarif and other moderates, who must persuade Supreme Leader Ayatollah Khamenei and other hardliners that Tehran can keep at least some of its nuclear-energy program—and its dignity—while stopping verifiably short of the bomb.