When contemplating a nuclear attack on the United States, Americans generally think of one or two scenarios: a nuclear-armed ballistic-missile attack or a terrorist strike utilizing nuclear materials smuggled into a large city and detonated there. But an attack could take the form of an atomic-generated electromagnetic pulse (EMP) strike, which could destroy electronic systems and power grids.
Such an attack “is one of a small number of threats that has the potential to hold our society extremely at risk and might result in the defeat of our military forces,” a federal commission reported in 2004. That panel — known officially as The Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack — was created by Congress in 2001 to counter the possibility that a hostile force might launch an EMP attack against the United States: specifically, detonating a nuclear weapon anywhere from 25 miles to several hundred miles above the Earth’s atmosphere.
The blast would do immense damage to anything with electronic wiring - including cars, computers, airplanes and communication lines - depending on the location of the attack and how well protected the wiring is. A nuclear weapon detonated at an altitude of 250 miles over the central United States would be capable of causing damage covering all of the continental United States as well as parts of Canada and Mexico.
And there are plenty of potential adversaries who may soon have the technological capability to carry out such an attack. In March 8, 2005, testimony before the Senate Judiciary Subcommittee on Terrorism, Technology and Homeland Security, Lowell Wood, acting chairman of the panel, noted that a Scud missile launched from a freighter off the Atlantic Coast could permit a terrorist organization to launch an EMP attack. “Scud missiles can be purchased inexpensively [for about $100,000] by anyone, including private collectors, in the worlds’ arms markets. Terrorists might buy, steal, or be given a ‘no fingerprints’ nuclear weapon. For example, North Korea has demonstrated willingness to sell both missiles and nuclear materials,” Mr. Wood said. “Iran, the world’s leading sponsor of international terrorism” is “known to have successfully test-launched a Scud missile from the Caspian Sea, a launch mode that could be adapted … to support an EMP attack against the United States from the sea.” Also, Iran has conducted high-altitude tests of the Shahab III missile in mode consistent with an EMP attack, and Iranian military literature has included references to the damage that such a nuclear blast could do to U.S. military capabilities.
In testimony before the House Armed Services Committee last month, EMP commission chairman William Graham noted that China and Russia have also considered limited nuclear attack options. In May 1999, during NATO’s bombing of the former Yugoslavia, senior members of the Russian Duma, during a meeting with a congressional delegation, suggested that Moscow might launch an EMP attack that could paralyze the United States. In testimony before the same congressional panel in June, Assistant Secretary of Defense James Shinn noted that China’s military is working on EMP weapons that can destroy electronic systems. “The consequence of EMP is that you destroy the communications network,” Mr. Shinn said. “And we are, as you know, and as the Chinese also know, heavily dependent on sophisticated communications, satellite communications, in the conduct of our forces. And so, whether it’s from an EMP or it’s some kind of a coordinated [anti-satellite] effort, we could be in a very bad place if the Chinese enhanced their capability in this area.”
There are preventive measures that can be taken, including urging utility companies to take steps to protect the nuclear grid, as the commission recommended. Few utilities have done so. In the end, the best way to deter a potential adversary from using such a system against the United States is to deploy a robust missile defense system, including space interceptors.