Sounds like a great plot for a post-apocalyptic thriller. Oh wait...

One year later, the U.S. military arrives to rebuild and aid the town. It is revealed that the EMP that devastated the contiguous United States was generated by three nuclear missiles launched from offshore container ships. One was launched from the Gulf of Mexico and detonated in the upper atmosphere over Utah, Kansas, and Ohio. The container ship was sunk by an explosion immediately after the missile launch; no indication remained of who was directly responsible for the attacks. Another missile was fired from off the Icelandic coast and detonated over Russia. Another nuclear missile was detonated over Japan and South Korea. The U.S. government is said to have believed that an alliance between Iran and North Korea was responsible for the attacks, and that the United States attacked Iran and North Korea with nuclear weapons in retaliation. It was also mentioned that the U.S. withdrew all of its overseas military forces back to the United States to aid in rebuilding and humanitarian work. It is also revealed that the EMP attack brought down Air Force One, killing the U.S. President.
[link to en.m.wikipedia.org]