Another utter hysterical statement to scare people. Listen, Iran has no nukes, and the US or Israel would never use one. Case closed. W.H. O. should be more worried about that nutbar in North Korea unleasing one.
Likelihood? We don't know where all the canisters are. Now that Iran is landing some punches ... would they load one up so it can be blown apart and spread all over by a defending patriot missile? Then would happen?