President Richard Nixon’s historic gamble with Mainland China turned out well. When he was elected in 1968, it was an out-of-control society and regime, subverting its neighbors and condemning the United States. Today we have a similar regional foe — Iran. Will President Obama be in Tehran a year from now, celebrating the start of a similar moderation by the world’s chief sponsor of terrorism? Or will he have rewritten yet another campaign pledge ushering in an Islamist nuclear power with apocalyptic ambitions?