Electromagnetic Pulse (EMP) Attack: A Preventable Homeland Security Catastrophe
By Jena Baker McNeill and Richard Weitz, Ph.D.
October 20, 2008

A major threat to America has been largely ignored by those who could prevent it. An electromagnetic pulse (EMP) attack could wreak
havoc on the nation's electronic systems-shutting down power grids, sources, and supply mechanisms. An EMP attack on the United
States could irreparably cripple the coun­try. It could simultaneously inflict large-scale damage and critically limit our recovery abilities.
Congress and the new Administration must recognize the signifi­cance of the EMP threat and take the necessary steps to protect
against it.

Systems Gone Haywire

An EMP is a high-intensity burst of electromagnetic energy caused by the rapid acceleration of charged particles. In an attack, these
particles interact and send electrical systems into chaos in three ways: First, the electromagnetic shock disrupts electronics, such as
sensors, communications systems, protective systems, computers, and other similar devices. The second component has a slightly
smaller range and is similar in effect to lightning. Although protective measures have long been established for lightning strikes, the
potential for damage to critical infrastructure from this component exists because it rapidly follows and com­pounds the first
component. The final component is slower than the previous two, but has a longer dura­tion. It is a pulse that flows through electricity
trans­mission lines-damaging distribution centers and fusing power lines. The combination of the three com­ponents can easily cause
irreversible damage to many electronic systems.[1]

An EMP attack on the United States could mate­rialize in two forms: nuclear and non-nuclear. The most devastating form, and most
difficult to achieve, is an EMP that results from a nuclear weapon. This form destroys any "unhardened" elec­tronic equipment and
electric power system- which means virtually any civilian infrastructure in the United States. The pulse occurs when a nuclear weapon
explodes above the visual horizon line at an altitude between 40 and 400 kilometers. The deto­nation of the nuclear warhead releases
photons in the form of gamma radiation and x-rays. These energetic particles scatter in every direction away from the blast. Many of
the particles descend and interact with the magnetic field lines of the Earth, where they become trapped. The trapped electrons then
create an oscillating electric current within the field, which rapidly produces a large electromag­netic field in the form of a pulse. Once
the pulse reaches electronic equipment, it negatively interacts with them and either disables, damages, or destroys them. An EMP
generated by a nuclear weapon could affect all critical infrastructures that depend on electricity and electronics within the vicinity of
the nuclear warhead blast radius. A nuclear weapon with a burst height of approximately 100 kilometers could expose objects located
within an area 725 miles in diameter to the effects of EMP.[2]

A non-nuclear, or improvised, EMP is a radio-frequency (rather than gamma or x-ray frequency) weapon. While easier to conceal and
not requiring a missile, a non-nuclear EMP must be detonated close to the target and does not produce as much damage as the
nuclear version, affecting largely localized areas.[3] But such a weapon could be harnessed as an "E-Bomb" (electromagnetic bomb), a
stand-alone weapon that is easier to hide and maneuver. It is dif­ficult to estimate the exact damage of an improvised attack, but in
1993 EMP testing by the U.S. military shut down engine controls 300 meters away at a contractor site.[4] Not large-scale by any means,
but damaging enough to cause concern.

It was not until the United States began high-alti­tude testing of nuclear weapons over the Pacific in the early 1960s that the potentially
devastating effects of EMP on even distant ground targets attracted widespread attention within the U.S. defense community. In the
1962 Starfish Prime test, during which a nuclear weapon was detonated 400 kilometers (250 miles) above Johnston Island in the Pacific,
electrical equipment more than 1,400 kilo­meters (870 miles) away in Hawaii was affected. Street lights, alarms, circuit breakers, and
commu­nications equipment all showed signs of distortions and damage.[5]

In 1997 and 1999, the House National Security Committee and the House Military Research and Development Subcommittee held
hearings on the potential threats to civilian systems in America from an EMP attack. Congress subsequently established the
Commission to Assess the Threat to the United States from an Electromagnetic Pulse (EMP) Attack, also known as the Graham
Commission after its chairman, William Graham (former science advisor to President Ronald Reagan). The Commission issued a report
in 2004 that evaluated the threat to the U.S. from an EMP attack, assessed vulnerabili­ties in both military and civilian systems, and
offered recommendations for overcoming these weaknesses. The Commission recommended hard­ening key power nodes as well as
storing spares of essential but hard-to-build components of the U.S. electric grid and other critical infrastructure for communications,
finance, and emergency public services.[6] Congress held hearings the same year to evaluate the Commission's recommendations,
but little tangible progress followed.[7] The Commission was re-established in 2006 to continue monitoring the EMP threat.

A few select sites have been hardened against an EMP attack since the threat was identified. Air Force One, the airplane that carries
the U.S. President, is designed to withstand an EMP attack. During the Cold War, the U.S. military hardened its most important military
systems, such as U.S. nuclear weapons systems, against EMP threats. These efforts have decreased since the end of the Cold War,
despite the continued vulnerability of these sys­tems. Presently, most efforts to counter the EMP threat are focused on initiatives to
stop the prolifer­ation of nuclear weapons and ballistic missiles. These efforts include programs like the Proliferation Security
Initiative, the Cooperative Threat Reduc­tion Program, and the Global Initiative to Combat Nuclear Terrorism.

Comprehensive threat assessment and scenario planning for EMP attacks remain underdeveloped. This inaction is in the face of
warnings, such as the one in the 2006 Quadrennial Defense Review(QDR)which stated clearly that the "expanded reli­ance on
sophisticated electronic technologies by the United States, its allies and partners increases their vulnerability to the destructive
effects of electro­magnetic pulse (EMP)."[8] Yet, the Department of Defense has not implemented the QDR's proposed EMP Action
Plan.[9] Meanwhile, the Department of Homeland Security (DHS) has focused on other urgent threats, such as from conventional
explosive devices or chlorine bombs, concluding that EMP is simply not a large enough threat for its attention. Even the National
Infrastructure Protection Plan (NIPP), the plan dedicated to ensuring that U.S. critical infrastructure is protected from terrorist attack,
does not directly address the EMP threat. Congress has recently reassumed its leadership role on EMP by holding hearings on the
issue in July 2008, but its ability to compel executive branch action in this area is limited.

While many non-federal homeland security authorities in many U.S. states express concern about an EMP attack, a comprehensive
survey found that state-based emergency responders and National Guard units have done little to prepare for such an incident.[10]
Alaska, perhaps because of its relative isolation from most federal emergency response assets and the state's vulnerability due to its
reliance on satellite-based communications, is a notable exception. In May 2007, the Alaskan state govern­ment announced it would
include EMP when it next revises its emergency response plan. The state's homeland security officials plan to address the
vul­nerability of the state's electric and telecommunica­tions infrastructures as well as related integration, implementation, and
survivability issues.[11] Alaska's efforts are considerable in comparison to other states; most have not even touched the issue.
Lim­ited state preparedness for an EMP attack is espe­cially dangerous given the inability of the U.S. government, itself mostly
unprepared for an EMP strike, to render much if any immediate assistance.

Americans remain gravely ill prepared for an EMP attack. In fact, the average U.S. city has only three days worth of food and health care
provi­sions.[12] Most Americans do not have enough bat­teries to keep flashlights working for any period of time, much less generator
capabilities. And many of the country's most vulnerable citizens rely on the electricity grid for medical equipment, such as dial­ysis
machines. Even standard medication will be difficult or impossible to come by if EMP disables pharmacies and transportation networks.

A Weapon of Mass Disruption

EMP has been dubbed a "weapon of mass dis­ruption" because of its ability to devastate its target by disrupting electronic
infrastructure. The August 2003 Northeast Blackout that affected Ohio, New York, Maryland, Pennsylvania, Michigan, and parts of
Canada demonstrated the potential effects of a wide-area EMP attack. During that incident, more than 200 power plants, including
several nuclear plants, were shut down as a result of the electricity cutoff. Loss of water pressure led local authorities to advise
affected communities to boil water before drinking due to contamination from the failure of sewage systems. Many backup generators
proved unable to manage the crisis.

The day of the blackout brought massive traffic jams and gridlock when people tried to drive home without the aid of traffic lights.
Additional transpor­tation problems arose when railways, airlines, gas stations, and oil refineries also halted operations. Phone lines
were overwhelmed due to the high vol­ume of calls, while many radio and television sta­tions went off the air. Overall, the
blackout-which lasted only one day-cost $7 billion to $10 billion in spoiled food, lost production, overtime wages, and other related
expenses inflicted on more than one-seventh of the U.S. population.[13]

In the case of an EMP attack, depending on whether it is nuclear or improvised, the damage could easily prove more severe. An EMP
detonation could affect car and truck engines, aircraft ignition systems, hospital equipment, pacemakers, commu­nications systems,
and electrical appliances. Road and rail signaling, industrial control applications, and other electronic systems are all susceptible to
EMP. Electromagnetic energy on a radio frequency will travel through any conductive matter with which it comes into contact-from
electrical wires to telephone wires, even water mains-which can spread the effects to areas far beyond ground zero.

A successful EMP attack could result in airplanes literally falling from the sky; vehicles could stop functioning, and water, sewer, and
electrical net­works could all fail-all at once.[14] Food would rot, health care would be reduced to its most rudimen­tary level, and
there would not be any transporta­tion. Rule of law would become impossible to sustain; police departments would be overwhelmed.

Communication abilities would be limited, pre­venting federal, state, and local governments from communicating with one
another-severely limit­ing abilities to shift needed resources around the country. During the 2003 blackout, some commu­nications
systems remained intact. Cars and aircraft were not directly affected and rapidly resumed operation after the electrical system
recovered a few days later. In an EMP attack, however, the damage to power lines, supervisory control and data acqui­sition (SCADA)
control systems (for utility systems infrastructure), and commercial computers would very likely be permanent due to fused power
lines and lost data-which would require replacing the entire electric system in the affected area. One esti­mate warns that the likely
costs from the detonation of an EMP weapon over the Washington, D.C., met­ropolitan area could exceed $770 billion.[15] Millions of
Americans could suffer death or injury, and social chaos could ensue.

Besides the domestic consequences of an EMP attack, it would also be difficult for the U.S. to orga­nize a coherent retaliatory strike
against the aggres­sor. America's armed forces may simply be unprepared for an attack, or our national devasta­tion could prove too
distracting. Furthermore, it may be too difficult to rapidly determine the per­petrator of the attack, for instance, if a compact E-Bomb
were smuggled into the U.S. If a nuclear warhead is detonated in orbit, there is a strong potential for substantial damage to U.S. and
other satellites as well as any spacecraft in use at the time of the explosion. The military applications of such satellites are critical for
defense systems that rely on GPS guidance, such as ballistic missiles and many conventional military strike weapons. The adverse
impact on U.S. space-based communications, early-warning assets, fire-control systems, overhead sen­sors and imagery, and
geospatial intelligence would be substantial as well.

Near-term recovery could prove impossible because of America's dependence on extensive transportation networks and other
electricity-pow­ered infrastructures. America's infrastructure is highly interconnected, as was demonstrated during the blackout. A
problem in one part of the country can translate into problems across the United States, contributing immensely to lives lost and
property destroyed during an EMP attack.

Potential U.S. Adversaries Have the Knowledge-and the Capability

The range of actors that might attempt an EMP attack against the United States is obviously-and distressingly-large and includes
conventional mil­itary regimes, rogue states with limited conven­tional military capabilities, and terrorist groups that seek to inflict
catastrophic damage on America. Both Russia and China have dabbled in EMP tech­nology for decades.

There is evidence that suggests that certain Rus­sian nuclear weapons have already been optimized to generate enhanced EMP
effects.[16] Just this year, Russian scientists claimed to have developed a com­pact apparatus that can fit on a dining table. The
electromagnetic pulse associated with this device could amount to billions of watts of power in a sin­gle platform.[17] Analysts have
also identified Chi­nese military writings that discuss using EMP weapons in international conflicts.[18]

For countries less dependent on modern technol­ogies and electronics, including both rogue states like Iran and North Korea as well
as stateless terrorist groups, EMP provides a potential way to attack the United States through asymmetric means. EMPs could be
used to circumvent America's superior con­ventional military power while reducing vulnerabil­ity to retaliation in kind. It would
certainly not be impossible for a terrorist organization, especially if state-sponsored, to acquire or construct an unso­phisticated
ballistic missile (non-working Scuds are reportedly available on the open market for $100,000) and use it in an EMP attack against
Amer­ica.[19] Such a missile could be launched from a freighter in international waters and detonated in the atmosphere over the
United States without warning.

The materials used to build non-nuclear EMP weapons can be easily acquired or manufactured by moderately developed terrorist
groups with even limited financial resources. Although the potential impact is less, an improvised EMP could still inflict major damage.
The construction of a nuclear weapon is much more difficult and requires a good understanding of physics, electrical engineering, and
explosives; but these terror groups are actively seeking to gain this knowledge, and rogue states could see opportunity in
collaborating with these groups to accelerate the process.

The Time for Action Is Now

The U.S. cannot continue to ignore the EMP threat. While some progress has been made in hard­ening potential U.S. targets against
attack, including critical military and government systems, the vast majority of electrical systems are unshielded and unprotected,
especially in the civilian sector. If properly shielded, electrical devices and systems can generally survive even the strongest
EMPs.[20] Congress and the new Administration must:

Perform More Research on the Threat. Further research is needed in order to ensure that Amer­ica can respond to the EMP threat
appropriately without wasting government resources on flimsy or useless security measures. Although there are numerous methods
to harness EMPs capable of affecting electronic systems, there is still a theo­retical limit to what damage they can produce in terms of
both geographic size and intensity.

Some EMP weapons release just enough energy to disable small electrical devices while others can destroy all the electronic devices
and sys­tems within a city block. Altitude plays a major role in whether an EMP attack will be successful; lower heights typically expose
a smaller surface area to EMP damage. Some systems are simply more vulnerable to EMP attack than others, such as devices plugged
into power grids and commercial computer equipment. The U.S. gov­ernment must gain knowledge of the attributes and capabilities of
EMP and understand the amount of money, time, and effort that will be required for meaningful prevention. EMP research should also
include actions by Con­gress to simulate the effects of an EMP attack on Washington and other high-value targets and re-examine the
Graham Report recommendations.


Build a Comprehensive Missile Defense Sys­tem. The most likely method of EMP attack would be a ballistic missile armed with a
nuclear warhead. Building a comprehensive missile defense system would allow the U.S. to intercept and destroy a missile bound for
the United States. The mere implementation of such a sys­tem would go a long way to prevent an attack by dissuading those who wish
to carry out such actions and sending a clear message that the U.S. takes this threat seriously.

Those opposed to missile defense in Congress and elsewhere have attempted to paint such an endeavor as a waste of resources that
does noth­ing to further American security. 33 Minutes: Pro­tecting America in the New Missile Age, A Reader, a collection of essays by
pre-eminent defense scholars, emphasized the need for such mea­sures, and recent missile testing by Iran demon­strates that other
countries are actively involved in developing missile programs-which could be used against the U.S.[21]


Incorporate EMP Attacks into National Plan­ning Scenarios. The National Planning Scenar­ios are 15 all-hazards planning scenarios
used by federal, state, and local officials in disaster response exercises. The exercises can determine capabilities and needs and
address problems before a disaster instead of after the fact. Given an EMP attack's unique nature and its ability to paralyze the U.S.,
individualized preparation is necessary. EMP must be added to the list.


Develop a National Recovery Plan. The U.S. must identify the key power grid and telecom­munications infrastructure that is critical to
pre­serving our nation's core capabilities and create a National Recovery Plan. This risk-based approach recognizes that certain
infrastructure is key to recovery after an EMP attack. By taking measures to protect this infrastructure, we can lessen the recovery
time from an attack.

According to the National Fire Protection Associ­ation's (NFPA) "Standard on Disaster/Emergency Management and Business
Continuity Programs," a private company should prepare to function without electricity for a short period in order to maintain
uninterrupted operations.[22] While this time period will certainly vary by industry, encouraging the private sector to prepare in this
manner and to develop company recovery plans will allow the government to focus on bringing key infrastructure back online. The
private sector can move toward this goal by investing in more adequate infrastructure now.
A Threat too Big to Be Ignored

Although many in Congress and the White House tend to ignore the EMP threat, America's potential adversaries will not. To these
adversaries, EMP technology represents the opportunity to inflict-with relative ease-catastrophic and lasting damage on the United
States that could threaten our very existence. Preventing such an attack depends on the U.S. government's ability to understand the
very real chance and the devastating consequences of an EMP attack-and to take the actions necessary to prevent them.

Jena Baker McNeill is Policy Analyst for Home­land Security in the Douglas and Sarah Allison Center for Foreign Policy Studies, a
division of the Kathryn and Shelby Cullom Davis Institute for International Studies, at The Heritage Foundation and Richard Weitz,
Ph.D., is Senior Fellow and Director of Program Management at the Hudson Institute.
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