One year later, however, it is hard to find evidence that Iran has benefited from the Arab uprisings. In fact, Iran’s regional position has taken a big hit. With the partial exception of Yemen, Tehran has struggled to build new networks of influence with emerging Islamist actors. Meanwhile, Assad’s regime has been thoroughly delegitimized, expelled from the Arab League, and is wobbling in the face of nationwide protests. This, in turn, has created considerable anxiety for Hezbollah, the Lebanese militia that constitutes Iran’s chief non-state ally.

The perception of Iranian meddling has also decimated Tehran’s “soft power” appeal across the Arab world. Surveys conducted in Egypt, Jordan, Lebanon, Morocco, Saudi Arabia, and the United Arab Emirates by Zogby International show Iran’s reputation in free fall since the Arab Spring began. Just a few years ago, Iran enjoyed a strong majority of support among the populations of all these countries; as of July 2011, Iran had a net unfavorable rating in every country but Lebanon.

This is not just a temporary setback for Iran, but a sea change that could deeply undermine its regional ambitions. To be sure, the trajectory of the Arab Spring remains uncertain, and rising sectarian tensions and political backsliding in some countries may provide opportunities for Tehran to cause mischief. But several underlying dynamics suggest that Iran’s struggles will continue.