An EMP Attack is a part of asymmetrical warfare. What is asymmetrical warfare? It is warfare designed by an enemy that does not have the ability to win a war using conventional methods.
What is an EMP attack? Quite simply, it is exploding a small to medium nuclear device approximately 400 mile up in the atmosphere. It would cause little to no physical damage to the terrain below, or to those that live there. What it would do is introduce a massive EMP (Electro Magnetic Pulse) field to everything below it. This would effectively knock out all electrical generating equipment, cell phones, radios, televisions, computers, etc. The EMP would incapacitate most electrical circuits.
This would result in no electricity. No water pumps for local communities. No refrigeration. Most cars would be non-functional due to their reliance on computers to control their engines, etc. Most things that rely on electricity would be non-functional. Can you imagine what this would do to the United States? The only people we could communicate with would be those standing next to us, in person. Again, no radio, no TV, no internet.
Is this science fiction? No!!! Several military reports have already been presented to Congress on this matter. A Google or Yahoo or MSN search on the subject will reveal it is very real. But except for a few conservative news sources, such as Worldnetdaily, newsmax, and a few newspapers, this subject is being hidden from the American public. Yet Congress and our military are vividly aware of this threat.
Just one such article.
Iran has already said it is considering one of these to bring the United States to its knees. It doesn't take much. A Simple Scud missile (with a range of about 1200 miles) with a small nuclear warhead launched in international waters, aimed to detonate over the central U.S. would do the trick. Incapacitating the U.S., parts of Canada and Mexico too.