Strategy for Protecting and Preparing the Homeland Against Threats of Electromagnetic Pulse and Geomagnetic Disturbances [open pdf - 338KB]
"Extreme electromagnetic incidents caused by an intentional electromagnetic pulse (EMP) attack or a naturally occurring geomagnetic disturbance (GMD, also referred to as 'space weather') could 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, and expanding beyond the initial geographic regions. EMPs are associated with intentional attacks using high-altitude nuclear detonations, specialized conventional munitions, or non-nuclear directed energy devices. Effects vary in scale from highly local to regional to continental, depending upon the specific characteristics of the weapon and the attack profile. High-altitude electromagnetic pulse attacks (HEMP) using nuclear weapons are of most concern because they may permanently damage or disable large sections of the national electric grid and other critical infrastructure control systems. [...] For these reasons, the potential severity of both the direct and indirect impacts of an EMP or GMD incident compels our national attention. The Department of Homeland Security (DHS) has been actively analyzing the risk of the EMP-GMD problem set since its inception. The Strategy for Protecting and Preparing the Homeland Against Threats of Electromagnetic Pulse and Geomagnetic Disturbances (hereafter referred to as the 'DHS Strategy') represents the Department's first articulation of a holistic, long-term, partnership-based approach to confronting this challenge."
Department of Homeland Security: https://www.dhs.gov/