“If Osama bin Laden’s al-Qaeda — or the dictators of North Korea or Iran — had the ability to destroy America as a superpower, would they be tempted to try?

Wouldn’t that temptation be even greater if that result could be achieved with a single attack, involving just one nuclear weapon, perhaps even one of modest power and relatively unsophisticated design?

And, what if the attacker could be reasonably sure that the United States would not know who was responsible for such a devastating blow?

Unfortunately, that scenario is not far fetched. It is the conclusion of a report issued in 2004 by a blue ribbon commission created by Congress. The commission found that a single nuclear weapon, delivered by a ballistic missile to an altitude of a few hundred miles over the United States, would be “capable of causing catastrophe for the nation.”

How is that possible? By precipitating a lethal electromagnetic pulse (EMP) attack.

An Atmospheric Tsunami

A nuclear weapon produces several different effects. The best known are the intense heat and hyperpressures associated with the fireball and the accompanying blast.

But a nuclear explosion also generates massive outputs of other kinds of energy. These include the creation of intense streams of x-rays and gamma-rays. If those are unleashed outside the earth’s atmosphere, some of them will interact with the air molecules of the upper atmosphere.

The result is an enormous pulsed current of high energy electrons that will interact, in turn, with the earth’s magnetic field.

In an instant, an invisible radio frequency wave is produced — a wave of almost unimaginably immense intensity, approximately a million times as strong as the most powerful radio signals on the earth. The energy of this pulse would reach everything in line of sight of the detonation. And it would do so at the speed of light.

The higher the altitude of the weapon’s detonation, the larger the affected area would be. At a height of three hundred miles, for example, the entire continental United States would be exposed, along with parts of Canada and Mexico.

In 2000, concerned about EMP technology, Congress created the “Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack” (the EMP Threat Commission, for short). In its final report, presented in summer 2004, the panel warned that terrorists could indeed execute such an attack by launching a small nuclear armed missile from a freighter off the coast of the United States.

… the testimony Congress received from other sources strongly suggested that such a devastating attack was neither unlikely nor difficult to achieve. It seemed that there was, in fact, reason to be concerned that terrorists and rogue states might present an EMP threat to the United States.

Concerned members of congress received help from an unlikely quarter in May 1999, when Russia explicitly invoked the specter of an EMP attack on the United States.

Vladimir Lukin (the chairman of the Duma International Affairs Committee) assured a delegation of American legislators that Russia was not helpless in the face of U.S. led interventions:

Hypothetically, if Russia really wanted to hurt the United States in retaliation for NATO’s bombing of Yugoslavia, Russia could fire a submarine launched ballistic missile and detonate a single nuclear warhead at high altitude over the United States. The resulting electromagnetic pulse would massively disrupt U.S. communications and computer systems, shutting down everything.

This blunt statement succeeded in getting the attention of both parties in Congress. A second opinion was clearly needed. And on October 30, 2000, the EMP Threat Commission was established by law.

The EMP Threat Today

The EMP Threat Commission conducted a worldwide survey of foreign scientific and military literature to assess the knowledge and intentions of foreign states regarding an EMP attack. The survey confirmed that both the physics and the military potential of EMP are indeed widely understood in the international community.

The commission survey found that the following nations were knowledgeable about EMP: China, Cuba, Egypt, India, Iran, Saddam Hussein’s Iraq, North Korea, Pakistan, and Russia.

The commission also learned that some foreign military experts regard EMP attack as a form of electronic or information warfare, not primarily as a form of nuclear war. One of China’s leading military theorists has written:

Information war and traditional war have one thing in common, namely that the country which possesses the critical weapons such as atomic bombs will have “first strike” and “second strike retaliation” capabilities . . . .

As soon as its computer networks come under attack and are destroyed, the country will slip into a state of paralysis and the lives of its people will grind to a halt. (Su Tzu Yun, World War: The Third World War — Total Information Warfare, 2001.)

In Iran — the most unabashed state sponsor of international terrorism today — some theorists have argued that the key to defeating the United States lies in attacking its electronics. This is from an Iranian political military policy journal:

Once you confuse the enemy communication network, you can also disrupt the work of the enemy command and decision making center.

Even worse, today when you disable a country’s military high command through disruption of communications you will, in effect, disrupt all the affairs of that country. . . . If the world’s industrial countries fail to devise effective ways to defend themselves against dangerous electronic assaults, then they will disintegrate within a few years. . . . American soldiers would not be able to find food to eat nor would they be able to fire a single shot. (“Electronics to Determine Fate of Future Wars,” Nashriyeh e Siasi Nezami, 1999.)

And this implied threat may not be empty words. In addition to their successful ship launched Scud missile test, the Iranian military has reportedly performed tests of its Shahab 3 medium range ballistic missile in a manner consistent with an EMP attack scenario.”

http://www.worldtribune.com/worldtribune/05/front2453711.9284722223.html

A new device which may soon be on the market holds promise in allowing electronic equipment to be EMP hardened. Called the “Ovonic threshold device”, it has been created by Energy Conversion Devices of Troy, MI. The Ovonic threshold device is a solid-state switch capable of quickly opening a path to ground when a circuit receives a massive surge of EMP. Use of this or a similar device would assure survival of equipment during a massive surge of electricity.