I'm asking this out of complete ignorance. This type of weapon would take out anything electrical, right? Would it bring down an airplane? I assume it would take out the communications at airports, etc.
More specifically, it would take out anything electronic. That means on the battlefield it would take out computers, GPS, targeting, etc. It would essentially level the playing field for an low-tech army. EMP is one of the big dangers of atomic weapons (outside of murder-death-kill) and according to some stories is the reason the soviets kept so much of their equipment at a low-tech level - so it would operate after EMP devastated higher-level electronics.
My technical background is severely limited, but my guess is that any electronics not hardened against EMP is vulnerable in theory.
Interesting that the UBL tape talked about a 500 thousand dollar operation resulted in 500 billion dollars damage to the economy. I read somewhere that someone built a primitive FCG for about 500 dollars.
If you assume that AQ does not have a nuke (and I still think that is foolhardy), then this type of weapon would be up their alley. But it is not either/or.
9/11 was followed by anthrax. Attacks with weapons of mass disruption (like E-bombs) could be followed by attacks with weapons of mass destruction (or vice versa).
Hit once to disable the response and/or defenses.
Then hit again.
That was how we did Iraq the first time.
The first shot was a computer virus that disabled their radar net. Then the helicopters did their thing on the opening night of the war.
Reciprocity.