Tehran is already the subject of numerous sanctions, and has been since 1979. No one would argue that these sanctions have shown any notable success in changing Iranian behavior — that is, apart from moving it in a more aggressive direction, strengthening a siege mentality among Iran’s hardliners and undercutting moderates’ calls for engagement. Even granting Rubin’s questionable assertion that “the most effective diplomacy occurs… simultaneously with more coercive strategies,” it’s worth noting that a recent report from Rubin’s own employer, the American Enterprise Institute, concluded not only that IRPSA “might generate no significant change in Iranian policy in the short term,” but that “the group that should be the target of strengthened sanctions, the Islamic Revolutionary Guard Corps(IRGC), is least likely to be affected.”