The Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack, which delivered its recommendation to Congress in April 2004, went largely unnoticed. It is, therefore, natural to question whether electromagnetic pulse (EMP) weapons actually present a serious threat to the United States , relative to the other, more publicized threats of nuclear, chemical, biological, and radiological weapons (see this WAR Report). The following analysis represents the first part of a two-part series that will examine the degree of danger presented by EMP weapons. The first piece of this analysis will examine the threat of an EMP generated from a nuclear detonation in the upper atmosphere. The second piece, to be published in next week?s WAR Report, will address the threat of flux compression generators, which generate an EMP through conventional explosives.

The high altitude nuclear atmospheric tests conducted in 1962, codenamed ?Fishbowl,? demonstrated the effects of an electromagnetic pulse. These atmospheric tests caused a powerful pulse that disrupted radio stations and electrical equipment in Hawaii, some 800 miles away. These tests are solid evidence that the EMP generated from a high altitude nuclear explosion presents a real threat to critical infrastructure. The Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack predicted that an explosion some 200 miles above Kansas, the approximate center of the continental United States, could generate a pulse powerful enough to propagate across the entire country. Theoretically, this is correct. However, the amount of damage this EMP would cause is unclear. It is certain that a percentage of critical infrastructure would be damaged, but the extent and severity of that damage cannot be determined. First, electrical equipment that is turned off is less likely to be damaged. Second, certain components of critical infrastructure are hardened against electromagnetic attack. This is especially true of those maintained by the US military.