It was one of the great promises of Barack Obama's presidency: that the world might be transformed by the leadership of a President who had an African Muslim father, who lived in Indonesia as a boy and who offered a foreign policy vision that promoted talking to enemies above threatening them. The idea literally brought some of Obama's supporters, shell-shocked by the horror of Iraq, to tears. Not so his opponents, who warned that the idea was dangerously naive and that negotiating with the U.S.'s enemies was a formula for disaster.
Obama's vision didn't change the world overnight. For much of his first term, his critics claimed vindication, particularly when it came to Iran, which rejected his early olive branch and marched steadily toward nuclear weapons capability. But Obama's new nuclear deal with Tehran undermines that narrative. His biggest foreign policy gamble has achieved a success a tentative and fragile one, to be sure in a presidency desperately in need of forward momentum.
The deal could still go badly wrong, and the critics may yet be proved right. The U.S. and Iran are not friends, and serious people from Israel to Washington warn that Obama may find himself outfoxed by hard-liners in Tehran who still condone chants of "Death to America." It's also possible that the document signed by Secretary of State John Kerry in Geneva on Nov. 24 is the first step toward a legacymaking accomplishment, one that leaves the U.S. safer and the world more peaceful and meets that early promise of transformation through communication.