This is the real threat Iran could present. They do not have the munitions for a ground blast that will do anything besides fully piss us off (in addition to a pretty lofty local death count), BUT they do have the ability to launch a small bomb at a sufficient altitude to EMP fry some of the major east coast cities.

There is a pretty big snowstorm moving in this Thurs/Friday for the eastern seaboard -- couple that with an EMP & you have a major problem. Interesting thing is, a lot of people will think the lights went out due to the snowstorm until they put things together after all the other gadgets are found dead as well.