A critical challenge for this policy option is that, absent a clear Iranian act of aggression, American airstrikes against Iran would be unpopular in the region and throughout the world
........ Thus Washington cannot allow airstrikes against Iran to become a self-defeating course of action that undermines the other U.S. policies that this option is ultimately meant to enable.
Especially in the absence of a clear Iranian provocation, averting this paradoxical danger would be a major task for U.S. diplomats in the run-up to
such an air campaign. ..........The truth is that these all would be challenging cases to make.
For that reason, it would be far more preferable if the United States could cite an Iranian provocation as justification for the airstrikes before launching them. Clearly, the more outrageous, the more deadly, and the more unprovoked the Iranian action, the better off the United States would be. Of course, it would be very difficult for the United States to goad Iran into such a provocation without the rest of the world recognizing this game, which would then undermine it.
(One method that would have some possibility of success would be to ratchet up covert regime change efforts in the hope that Tehran would retaliate overtly, or even semi-overtly, which could then be portrayed as an unprovoked act of Iranian aggression.)