AMERICA'S VULNERABILITY TO A DIFFERENT NUCLEAR THREAT: AN ELECTROMAGNETIC PULSE.
Jack Spencer(1) © 2000
The destruction would result from the split-second release of a high-energy electromagnetic pulse (EMP) after a nuclear bomb is detonated miles above the Earth and outside the atmosphere
The Changing Fears
This destruction would result from the split-second release of a high-energy electromagnetic pulse (EMP) after a nuclear bomb is detonated miles above the Earth and outside the atmosphere. Within a week of the blast, although no one would be instantly killed, the disruption of food and water supplies and health care caused by the shutdown of transportation, computers, networks, electronic equipment, and communication systems would have serious consequences for millions of people. (2) Recovering from such an attack could take years.
The U.S. military first witnessed this phenomenon after a series of high-altitude nuclear tests in the Johnston Atoll in 1962 generated a disruption in electronic equipment in Hawaii, nearly 1,000 miles away. According to reports, the EMP interrupted radio broadcasts, caused streetlights to malfunction and burglar alarms to sound, and resulted in electronic failures across the islands despite their great distance from the test site.(3)
Little has been done to protect electrical systems from this threat beyond the nation's nuclear war-fighting infrastructure. The reason: During the Cold War, only the Soviet Union had the ability to mount an EMP attack against the United States, and if it had launched such an attack, the result would have been nuclear war. It made no sense to spend money to protect civil infrastructure from an electromagnetic pulse since little would be left standing after a nuclear bomb landed on U.S. soil.
Today, because of the spread of nuclear technology and ballistic missiles, the threat of a high-altitude EMP explosion over the United States or a battlefield is increasing. Indeed, America's reliance on advanced electronics makes its systems more vulnerable to such a blast than those of hostile states that might choose to use an EMP. Moreover, protecting all of America's civilian electronic infrastructure is fiscally not feasible. Because the most likely vehicles for delivering such a nuclear device above the atmosphere are ballistic missiles, the most prudent method of protecting America from EMP attacks would be a missile defense system that could destroy a ballistic missile before it reaches U.S. airspace.
Under what circumstances would an EMP attack on the United States be likely to occur? The possible scenarios range from one involving a rogue state's desire to demonstrate its potential ability to strike U.S. territory with a nuclear bomb to one in which such a state wants to give itself an advantage in a regional conflict by crippling U.S. military and allied forces, which are more dependent on advanced electronics and therefore more susceptible to an EMP attack.
Congress is well aware of the increasing threat. The Senate will have an opportunity to address the vulnerability of military and civilian systems to such an attack when it considers the fiscal year (FY) 2001 defense authorization bill (H.R. 4205) passed by the House on May 18. Representative Roscoe Barlett (R-MD) authored a provision of this bill (Title XIV) to establish a Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP) Attack. This would be an important first step.
In addition, Congress should hold hearings to establish what missile defense system could intercept ballistic missiles armed with nuclear warheads that could be detonated above the atmosphere, and it should continue to press the Administration to proceed quickly toward the deployment of an effective national missile defense system.
Understanding The EMP Threat
An EMP can have devastating consequences for developed countries, because any metallic conductor in the area affected becomes a "receiver" for the powerful energy burst released by the blast. Such receivers include anything with electronic wiring--from airplanes and automobiles to computers, railroad tracks, and communication lines. If systems connected to these receivers are not protected, they will be damaged by the intense energy pulse. Indeed, depending on the strength of the pulse and the vulnerability of the equipment, the effects could range from interrupted phone conversations and radio interference to the melting of components in every type of electrical system.
An EMP damages unprotected electronic equipment within the blast's "line of sight." The size of the area in harm's way (the EMP's "footprint" on the Earth's surface) is determined by the altitude of the explosion. The higher the altitude, the greater the land area affected (see Map 1 above). A Scud-type ballistic missile launched from a vessel off the U.S. coast and detonated at an altitude of 95 miles would degrade electronic systems across one-fourth of the United States. A Taepo Dong-2 missile launched from North Korea probably could deliver a warhead 300 miles above America--enough to degrade electronic systems throughout the country. Crude weapons with low yields, like those used against Japan in World War II, would have ample power to cripple the United States.
Possible EMP Scenarios
In the post-Cold War years, the proliferation of weapons of mass destruction makes the threat more difficult to assess. More important, the traditional deterrent of retaliation does not apply. No rogue nation has the capacity to fight a general nuclear war with the United States; therefore, it is not likely that an EMP blast would be used as a precursor to full-scale war. And since an EMP blast is not likely to kill anyone directly or to be followed by a nuclear strike that would annihilate U.S. cities, the United States is less likely to retaliate and destroy an entire nation of innocent people as punishment for the decisions of a rogue leader. The motivation for a rogue state to use its limited nuclear arsenal in an EMP strike against the United States is simple: It maximizes the impact of its few warheads while minimizing the risk of retaliation.
This decrease in risk for rogue leaders could compel them to use EMP to offset overwhelming U.S. conventional power on the battlefield. An EMP blast would debilitate U.S. forces in a hot spot where they might be deployed and throughout a region of strategic interest, such as Northeast Asia or the Middle East. Because the United States has no policy on deterrence for a rogue state's use of high-altitude EMP, and because EMP attacks are less risky for those states, such attacks are far more likely to occur in this era of nuclear proliferation than they were at any time during the Cold War.
The national missile defense architecture planned by the Administration, with 100 ground-based interceptors stationed at one site in Alaska, may be unable to intercept a nuclear warhead before it detonates above U.S. territory, and it would have virtually no chance of intercepting such a missile above a theater of combat.
Consider these possible scenarios.
Scenario #1: A rogue-state leader decides to launch an EMP attack on the United States to improve the odds of winning a regional conflict.
Scenario #2: An enemy explodes a nuclear device over a theater of combat or an area containing allied assets to cripple the United States.
Scenario #3: A surprise terrorist attack is launched against the United States, but the aggressor cannot be identified.
Scenario #4: An enemy uses an EMP blast as part of its war strategy against a U.S. ally.
Scenario #5: A rogue leader wants to attack the United States but evade retaliation.
How Vulnerable Is America?
The need to harden more systems is becoming more of an issue in light of the proliferation of nuclear know-how and ballistic missile technology to Third World countries--a serious threat that was made even clearer by the report of the congressionally mandated Rumsfeld Commission. Since the release of an unclassified summary of the commission's report in mid-1998, various U.S. Department of Defense officials have testified before Congress on the seriousness of an EMP attack. For example, Colonel Richard Skinner, the principal director of the Department of Defense's Command, Control, Communications, Intelligence, Surveillance, and Reconnaissance Unit and Space Systems, stated that "While an unlikely threat, EMP...weapons would have serious impact to military command and control systems." (9)
The commercial mass production of advanced electronic systems has made high-quality electronic devices exceedingly affordable, and slashed defense budgets force the U.S. military to look for cost savings wherever possible. Thus, the military increasingly has been purchasing commercial products for use in U.S. weapons systems. The new, advanced tactical Tomahawk cruise missile, for example, will use commercial electronics.(10) This disturbing fact is highlighted by the comments of the deputy chief of the Joint Chiefs of Staff's Command Center, Stanley Jakubiak: "[T]he military has...taken a simplistic approach. We've...assumed that all commercial equipment would fail under an EMP pulse."(11) Not only are many military systems vulnerable, but so are the systems that Americans rely on every day.
On July 15, 1996, President Bill Clinton issued Executive Order No. 13010, in which he identified eight infrastructure systems critical to the nation's survival: telecommunications, electric power systems, oil and gas storage, transportation, banking and finance, storage and transportation, water supply systems, and emergency services (including medical, police, fire and rescue, and continuity of government). Retired Air Force General Robert T. Marsh, chairman of the President's Commission on Critical Infrastructure Protection, has testified to the House National Security Committee that "the nuclear threat from hostile nations can not be dismissed today," and "a high altitude EMP attack could devastate the telecommunications and other critical infrastructure."(12) Although he conceded that the systems were vulnerable, he admitted that the Administration was "not considering any special measures to counter such a threat."(13)
Not everyone agrees about the effects of a high-altitude EMP for civil infrastructure. A 1991 study on the "Effects of Geomagnetic Disturbances on Electric Power Transmission Systems" published by the Electrical Power Research Institute, for example, points out that natural phenomena such as solar storms may cause more damage than an EMP blast.(14) But according to Dr. Gordon Soper, a former Defense Department official responsible for nuclear, chemical, and biological defense programs who testified before the House Small Business Committee, "an EMP attack would result in an unacceptable disruption and damage to our commercial electronic infrastructure."(15) Almost without exception, experts agree that a high-altitude EMP would damage America's electronics. They disagree about the extent of the damage and what should be done to prevent it.
Regardless of the debate, the surest way to protect the United States from a high-altitude EMP is to deploy a ballistic missile defense that would give the United States an opportunity to intercept and destroy a warhead before it is detonated above the atmosphere. This would prevent an EMP attack and any harm to U.S. systems, and it might even deter rogue leaders from considering the use of EMP. Deploying a missile defense architecture that is capable of intercepting a missile early in flight (during the ascent phase) means that rogue-state missiles would be ineffective, thereby undermining the rationale for their use.
Protecting Against High-Altitude EMPs
To protect electronics, an entire system must be encased in a metallic shield that prevents any external electromagnetic pulse from entering. Moreover, antennas and power connections must be equipped with surge protectors, windows must be coated with wire mesh or conductive coating, and doors must be sealed with conductive gaskets. Fiber optic cable is not vulnerable to EMP, but the switches and controls that use microelectronics in conjunction with the fiber optic cable are, and should be protected. Continuing efforts to replace copper communications cable with fiber optic cable will reduce overall EMP vulnerability significantly. And to ensure that protection lasts over the lifetime of the equipment, maintenance and testing should be performed on a system regularly. If a system is modified, fixed, or serviced, its EMP vulnerability should be assessed.
All of these steps can be affordable. Assuming these protections are engineered into a product or building from the outset would add as little as 1 percent to 5 percent to overall costs. (Retrofitting systems, however, could add substantial costs.) EMP surge protectors have become very inexpensive. According to George Ullrich, Deputy Director of the Defense Special Weapons Agency, such hardening is needed: "systems, such as commercial power grids [and] telecommunications networks... remain vulnerable to widespread outages and upsets due to high altitude EMP. While DOD hardens assets it deems vital, no comparable civil program exists."(16)
Because these steps have not been taken, there is little doubt among the experts that high-altitude EMPs will harm the systems that Americans and their armed forces rely on each day. Now the debate is over the extent of the vulnerability, the probability that it will occur, how to reduce the vulnerability, and how to respond to an attack.
What Congress Should Do
As if to confirm the Rumsfeld Commission's assessment, within two months of the report's release, North Korea tested a prototype ICBM. Because the United States cannot defend itself from even one ballistic missile, Congress reacted immediately to make it the policy of the United States to deploy a national missile defense system as soon as technologically possible.
This is even more important in light of the possible threat of high-altitude EMP blasts. All of the warning signs are present. The United States is increasingly reliant on vulnerable advanced electronics, and the weapons and missiles needed to mount an EMP assault are proliferating at a dangerous pace. Yet the U.S. military lacks a coherent policy on how to respond to an attack. America needs an authoritative voice--a blue-ribbon commission modeled after the Rumsfeld Commission--that can define the problem in realistic terms for Congress and recommend the steps to take to mount an adequate defense against the EMP threat.
The material displayed above was produced by the Kathryn and Shelby Cullom Davis Institute for International Studies and published by The Heritage Foundation 214 Massachusetts Ave., N.E., Washington, D.C., 20002-4999. The Intitute and the Foundation can be reached by calling (202) 546-4400 or by visiting their WEBSITE.