That's what I've been thinking for quite some time. A freighter mounted SCUD could deliver the EMP over New York and paralyze the electrical grid system and put every car, motor, computer out of commission permanantly. Too bad other posters believe that Iran is so archaic that they're incapable of doing this.
"A Massive Electromagnetic Pulse Could Collapse The Economy In A Single Moment "
http://www.infowars.com/a-massive-electromagnetic-pulse-could-collapse-the-economy-in-a-single-moment/
The Iranians are patient, through, observant, intelligent and the clerical regime is utterly determined to (1) survive and rule and (2) restore Persia's glory and (3) avenge themselves on those who they see as the sources of their degradation through the Shah's regime (the US, Great Britain and Israel). We underestimate them at our peril.