An electromagnetic pulse (EMP) attack is one of the “huge” potential threats that the Federal Bureau of Investigation (FBI) worries about. At least that is what Art Cummings, a deputy assistant director in the agency’s Counterterrorism Division, told Ronald Kessler in an interview for Kessler’s new book The Secrets of the FBI.

An EMP is a high-intensity burst of electromagnetic energy caused by the rapid acceleration of charged particles. The burst causes disruption of an electromagnetic system and fries electronic devices within its line of sight. Depending on its intensity, an EMP could instantly send the United States back to the 19th century. An EMP is one of the results of a nuclear weapon explosion, but non-nuclear weapons and geomagnetic storms can cause it as well. Despite the FBI’s recognition, the United States remains largely unprotected from the effects of an EMP.

The most effective way to cause an EMP is to detonate a nuclear warhead at a high altitude. A ballistic missile could be the means for such an attack. Iran and North Korea possess ballistic missile capabilities that would allow them to target the U.S. homeland and U.S. allies in Europe and the Middle East. North Korea has nuclear weapons, and Iran is well on its way to obtaining these as well. The Russian Federation and China have EMP capabilities and delivery means. In addition, their nuclear warheads can be augmented to create a stronger EMP blast and lower radiation fallout. But an EMP, albeit on much smaller scale, could be created by a lone terrorist with right equipment. If the electrical power grid were destroyed, it would take years to replace critical transformers, since only a few countries build them; it takes more than a year to make one transformer.

Fortunately, the United States has the means to protect itself at its disposal. For about $200 million, the United States can harden the major transformers associated with large metropolitan areas and protect populations of these cities from an effect of an EMP attack. In addition, a robust missile defense system comprised primarily of Aegis ballistic missile defense capable ships; Aegis Ashore, a land-based missile defense component; and Unmanned Aerial Vehicle capabilities can deprive the opponent of the opportunity to deliver a nuclear warhead on a ballistic missile and cause an EMP in the first place. The U.S. government must not hesitate to provide for the common defense.