Number: RL32544 Title: High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments Authors: Clay Wilson, Foreign Affairs, Defense, and Trade Division Abstract: Electromagnetic Pulse (EMP) is an intense energy field that can instantly overload or disrupt numerous electrical circuits at a distance. Modern high technology microcircuits are especially sensitive to power surges, and the possible vulnerability of U.S. civilian computer systems to the effects of EMP has been discussed in the media. EMP can be produced on a large scale using a single nuclear explosion, and on a smaller, non-nuclear scale using a device with batteries or chemical explosives. Several nations, including reported sponsors of terrorism, may currently have a capability to use EMP as a weapon for cyber warfare or cyber terrorism, to disrupt computers, communications systems, or parts of the U.S. critical infrastructure. Policy issues raised by this threat include (1) what is the United States doing to protect civilian critical infrastructure systems against the threat of EMP, (2) does the level of vulnerability of U.S. civilian and military electronics to large-scale EMP attack encourage other nations to develop or acquire nuclear weapons, and (3) how likely are terrorist organizations to launch a smaller-scale EMP attack against the United States? Pages: 16 Date: March 26, 2008