The best case—maybe even the only good case—for Barack Obama’s Iran deal is the one he’s not making. It’s this: The deal is an experiment. It’s a test of Iran, and one that can quickly be reversed by the U.S. Congress if necessary because it’s not a binding treaty. What I’m saying is the deal could be viewed and marketed as a modest effort, an exercise that’s worth the risk because everyone acknowledges Iran is not yet a full-blown nuclear state. Obama could say that we’ve tried sanctions and they didn’t succeed in slowing down Iran, so we are now going to try ending the sanctions and see if Iran responds to more positive incentives—with the understanding that if Iran’s response proves disappointing rather than encouraging, we will return to doing what we can to cripple the regime or deliver an American military strike to destroy the country’s nuclear sites.