There’s a lot of chatter about Iranian EMP again (it seems to come back periodically). here’s Walid Phares over at the Counterterrorism Blog:
Over the past seven months I have been interacting with US Homeland Security and European defense officials and experts on a the potential next threat to the West, more particularly against mainland America. The signature of that strategic menace is EMP: Electro Magnetic Pulse; a weapon of the future, already available in design, construction and possible deployment. As eyes are focused on the Iranian nuclear threat, and as we began recently to understand that the missile advances are as important then the fissile material development, attention is now being drawn by private sector projects and some in the defense world to what can cause a wider circle of damages and thus more deterrence against US national security.
In short, and I borrow from the Project “Shield America.org,” an electromagnetic pulse (EMP) attack could be triggered by a nuclear warhead detonated at high altitude over America. The resulting blast would create an EMP, a shockwave that could “cripple military and civilian communications, power, transportation, water, food, and other infrastructure.” Even if a high-altitude EMP kills nobody at first, it would paralyze a large section of the United States. The lingering practical and economic effects would take anywhere from hours to years to resolve: when secondary effects are considered, an EMP could be even deadlier than a direct nuclear strike against the mainland. Indeed, Rep. Roscoe Bartlett has written: “Where the terrorist airliner attacks of 9/11 killed thousands, a terrorist EMP attack could indirectly kill millions and conceivably cause the permanent collapse of our entire society.”
I’ve written about that before, and done a little bit of math on it. I’m certainly no arms control wonk, but what I came away with was the belief that it would take a 1 MT weapon detonated about 19 – 20 miles up to have a meaningful impact as opposed to a relatively local impact.
I’ve gotta believe that no new nuclear power is likely to come out of the box with a 1 MT weapon, and that the technology to get it 20 miles above New Jersey isn’t something that Iran will be able to do soon enough – reliably enough (remember, no do-overs on something like this) to risk their national survival on a prototype.