An EMP is a result of a nuclear bomb which has been set off in the upper atmosphere. Tests were done in the early 1960’s. See “Starfish Prime”:
http://en.wikipedia.org/wiki/Starfish_Prime
Scroll down and it talks about damage done to the grid in Hawaii.
If Starfish Prime had been a little lower and not 900 miles away, it would have had massive effects on Hawaii electronics, communications and electrical systems.
See how power-lines in the old USSR captured the EMP from one of their tests and fed back into the plant setting it on fire:
http://en.wikipedia.org/wiki/Electromagnetic_pulse
True. However, all nuclear bombs give off an EMP burst. An upper atmosphere detonation allows the burst to spread and maximizes the area it can reach, AND (this is the important part), keeps the nuclear bomb from destroying the infrastructure.
The goal of the ruling elite who set up and control all wars is to KILL PEOPLE without DESTROYING THE VALUABLE RESOURCES.
Granted, most of our tests were underground and the ground absorbed most of the EMP pulse, so loss of electrical power on a widescale basis didn't happen. I think if we endure a nuclear weapon explosion over the US, big enough to cause a massive failure of the electric grid, that we will have more to worry about than no electricity. Besides the socialists,commies, and Muslims are taking us over from the inside, so there will be no more wars with nuclear bombs.