An electromagnetic pulse (EMP), triggered by a high-altitude detonation of a nuclear weapon, poses a considerable threat to our national security and is one of a small number of weapons that could be used to bring the whole of America to its knees. An EMP attack would strike what has become the United States' Achilles heel - its relatively unprotected, yet vital, technological infrastructure.
An electromagnetic pulse is generated when a nuclear weapon is detonated above the earth's surface (at altitudes between 40-400 km). In such instances, the nuclear blast would interact with the Earth's atmosphere, ionosphere, and magnetic field to produce an EMP. In addition to the direct effects of the blast, the EMP would impact electrical systems across a wide geographical area. The amount of damage depends primarily on the altitude of the blast and the size of the nuclear warhead.
Our growing dependence upon computers and other electrical systems has made us especially vulnerable to an electromagnetic pulse attack.
An EMP could cripple the U.S. by knocking out electrical power, telecommunications and transportation, along with banking and financial networks. The loss of power would also limit our access to fuel and emergency services, as well as food and water supplies. Systems could be down for weeks, months, or even years. It would be as if the United States slipped back into the 19th century - before the advent of cell phones, computers, microwaves and many of the other modern conveniences on which we now depend.
It has been nearly a year since the Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack released its findings. Its assessment was largely overshadowed by the report of the 9/11 commission, and thus did not garner much attention from the mainstream media. Dr. Lowell L. Wood, acting chairman of the commission, described the nature of an EMP attack:
"...electromagnetic pulses propagate from the burst point of the nuclear weapon to the line of sight on the Earth's horizon, potentially covering a vast geographic region...simultaneously, at the speed of light. For example, a nuclear weapon detonated at an altitude of 400 kilometers over the central United States would cover, with its primary electromagnetic pulse, the entire continent of the United States and parts of Canada and Mexico."
Senator Jon Kyl, who chairs the Senate Subcommittee on Terrorism, Technology, and Homeland Security, wrote the following about the EMP threat in the April 15 edition of the Washington Post:
An electromagnetic pulse attack on the American homeland is one of only a few ways that the United States could be defeated by its enemies - terrorist or otherwise. And it is probably the easiest. A single Scud missile, carrying a single nuclear weapon, detonated at the appropriate altitude, would interact with the Earth's atmosphere, producing an electromagnetic pulse radiating down to the surface at the speed of light. Depending on the location and size of the blast, the effect would be to knock out already stressed power grids and other electrical systems across much or even all of the continental United States, for months if not years.
Few if any people would die right away. But the loss of power would have a cascading effect on all aspects of U.S. society. Communication would be largely impossible. Lack of refrigeration would leave food rotting in warehouses, exacerbated by a lack of transportation as those vehicles still working simply ran out of gas (which is pumped with electricity). The inability to sanitize and distribute water would quickly threaten public health, not to mention the safety of anyone in the path of the inevitable fires, which would rage unchecked. And as we have seen in areas of natural and other disasters, such circumstances often result in a fairly rapid breakdown of social order.
Starfish Prime
The existence of the electromagnetic pulse has been known since the 1940s, when nuclear weapons were being developed and tested. However, because of a lack of data, the effects of an EMP were not fully known until 1962. At this time, the United States was conducting a series of high-altitude atmospheric tests, code named "Operation Fishbowl," in the Pacific Proving Ground. On July 9, 1962, a test known as "Starfish Prime" was conducted near Johnston Island at an altitude of about 400 kilometers. This 1.4 megaton bomb caused an EMP that disrupted radio stations, destroyed street lights, shut down automobiles and wreaked havoc on electrical equipment throughout the Hawaiian Islands, some 1,400 kilometers away from the site of the blast!
The explosion even disrupted radio equipment as far away as Australia (the cause of the malfunctions was kept quiet). Consequently, in 1963, the United States and the Soviet Union signed the Atmospheric Test Ban Treaty to counter the considerable threat posed by EMPs.
Researchers concluded that the electrical disturbances caused by Starfish Prime were the result of something known as the Compton Effect, theorized by physicist Arthur Compton in 1925. (Compton's assertion was that photons of electromagnetic energy could knock loose electrons from atoms with low atomic numbers.)
Photons from the nuclear blast's intense gamma radiation knocked a large number of electrons free from oxygen and nitrogen atoms in the atmosphere. This flood of electrons interacted with the Earth's magnetic field to create a fluctuating electric current, which induced a powerful magnetic field. The resulting electromagnetic pulse induced intense electrical currents in conductive materials over a wide area.
I recently had a discussion with Dr. William Graham, who is regarded as one of the most senior analysts within the "strategic community." He highlighted that an EMP device over the Midwest could disable the electric and electronic services to over 70% of the population.
Non-Nuclear EMP Weapons
It is important to note that an EMP of a lesser magnitude can be generated without the use of a nuclear weapon. The United States most likely has various non-nuclear EMP weapons or "e-bombs" in its arsenal, but it is not clear in what form. If they do indeed exist, they are still classified. However, we do know that much of the United States' EMP research is conducted at a laboratory at Kirtland Air Force Base in New Mexico and involves high-power microwaves. According to a study done for the Australian Air Force, the most likely way of creating weaponized high-powered microwaves is through a device known as a vircator.
Because the source of the energy is a compact explosive, a vircator could fit inside bombs or cruise missiles. Deployed, they could disrupt a variety of enemy systems, from missile targeting and launch electronics to command-and-control systems. It is possible that they could penetrate hundreds of meters below the ground and reach underground bunkers. Larger, reusable weapons are also being developed for use on ships to disable incoming missiles such as China's Silkworm.
An Imminent Threat
Both China and Russia are capable of executing an EMP attack. Furthermore, we know that both nations have considered the use of an EMP as part of a strategy to defeat the United States in battle. Russia in particular has a sophisticated understanding of EMP. During the test era, the Soviet Union did high-altitude atmospheric tests over its own territory, impacting civilian infrastructures. In May 1999, during the NATO bombing of the former Yugoslavia, high-ranking members of the Russian Duma alluded to a Russian EMP attack that could paralyze the United States.
However, according to some experts, the more imminent threat to the U.S. is not Russia or China, but rogue states such as Iran and North Korea - and their terrorist allies. CIA Director Porter Goss recently testified before Congress about nuclear material missing from storage sites in Russia that may have found its way into terrorist hands, and FBI Director Robert Mueller has confirmed intelligence that suggests al Qaida is trying to acquire and use weapons of mass destruction. An EMP would have adverse effects on a larger geographical area and could be more easily orchestrated than a targeted nuclear attack on an American city. For this and other reasons, terrorists and rogue nations that possess relatively unsophisticated missiles armed with nuclear weapons may find an EMP to be the most effective means of assault.
Terrorists planning to launch a nuclear weapon over American soil may sound like the plot of a Hollywood movie, but this isn't science fiction. The threat of an EMP attack is very real.
Thomas C. Schelling, an economist and professor of foreign affairs, national security, nuclear strategy and arms control at the University of Maryland School of Public Policy, once wrote that we have "a tendency in our planning to confuse the unfamiliar with the improbable. The contingency we have not considered looks strange; what looks strange is therefore improbable; what seems improbable need not be considered seriously."
Those words were written in regards to the Japanese attack on Pearl Harbor. In that instance, American forces were taken by surprise and the result was catastrophic. Have we learned from our mistake or is history destined to repeat itself? Will we once again be taken by surprise by our adversaries? To some, an electromagnetic pulse may seem strange or even improbable, but we would be foolish not to take it seriously.
