If the above was the danger of conventional warfare, asymmetrical warfare is shown below:
One Second After by William R. Forstchen, PhD
New York Times best selling author William R. Forstchen now brings us a story which can be all too terrifyingly real...a story in which one man struggles to save his family and his small North Carolina town after America loses a war, in one second, a war that will send America back to the Dark Ages...A war based upon a weapon, an Electro Magnetic Pulse (EMP)
I was just looking at this yesterday after someone else recommended it.
In the same conversation, someone mentioned The X-Events: The Collapse of Everything, which apparently has a section on an EMP attack. I haven't read it and can't personally recommend, but if you like the subject matter and since EMPs are getting a lot of press thanks to a series of R candidate mentions, I thought I'd through it out there.