Electromagnetic Pulse

Extreme electromagnetic incidents caused by an intentional electromagnetic pulse (EMP) attack have the potential to damage significant portions of the nation’s critical infrastructure, including the electrical grid, communications equipment, water and wastewater systems, and transportation modes. The impacts are likely to cascade, initially compromising one or more critical infrastructure sectors, spilling over into additional sectors or geographic regions, and adversely impacting millions of households and businesses.

Overview

EMPs are associated with intentional attacks using high-altitude nuclear detonations, specialized conventional munitions, or non-nuclear directed energy devices. Effects can range from highly local to regional to continental, depending upon the nature of the incident. High-altitude electromagnetic pulse attacks (HEMP) are of most concern because they may damage or disable large sections of the national electric grid and other critical infrastructure control systems.

Any electronics system that is not protected against extreme EMP events may be subject to either the direct “shock” of the blast itself or to the damage that is inflicted on the systems and controls upon which they are dependent.

EMP Risk

Extreme EMP incidents fit into the categorization of “hard problems”—both are low probability/high consequence scenarios that challenge effective policymaking.

A HEMP attack by an adversary with basic nuclear weapons and missile capabilities may be disruptive on a regional scale but is unlikely to cause catastrophic damage to the U.S. electric grid on a continental scale. Adversaries with highly developed nuclear capabilities might cause widespread harm to U.S. infrastructure with complex HEMP attacks in the context of an escalating international conflict.