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Are nuclear weapons a more dangerous source of EMP than solar storms? (credit: NASA)

Rebuttal to “The EMP threat: fact, fiction, and response”

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Yousaf M. Butt in “The EMP Threat: Fact, Fiction, and Response” (The Space Review, Part 1, January 25, 2010 and Part 2, February 1, 2010) casts aspersions on the competence and honesty of the congressionally mandated Commission To Assess The Threat To The United States From Electromagnetic Pulse (EMP) Attack. Dr. Butt alleges that the EMP Commission’s finding that terrorists or rogue states could make a potentially catastrophic nuclear EMP attack on the United States is “overblown.”

We are concerned that the article will misinform the public and scientific community on a vitally important issue of national security policy, and so seek to correct the record with this rebuttal. The rebuttal offered here is ours and is not an official response from the EMP Commission. (It is noted that the terminology in this discussion paper will use EMP (a general term) and (high-altitude electromagnetic pulse) HEMP interchangeably. It is noted that the terms E1 HEMP and E3 HEMP are only defined in this manner.)

Dr. Butt asserts that, “The methodology and conclusions of the EMP commission have already been criticized a few years ago.” To substantiate his claim, Dr. Butt references articles such as “The Newt Bomb” in The New Republic—none are serious scientific studies but merely political cartoons, authored by persons who have no competence to judge the EMP Commission’s work, and who obviously never even read the EMP Commission reports. For example, these articles condemn the EMP Commission for advocating National Missile Defense and preemptive war against Iran. Yet the EMP Commission never made any such recommendations.

EMP Commission background

Dr. Butt neglects to tell his readers anything about the purpose and qualifications of the EMP Commission, not even offering a footnote on the EMP Commission reports so that readers can investigate the reports for themselves, presumably because this would not advance Dr. Butt’s agenda.1

Congressional commissions, like the EMP Commission, are instruments of last resort, established when departments and agencies and the Congress can achieve no consensus on a controversial issue vital to the national interest. Typically, commissioners are senior statesman and nationally recognized scientists or experts, selected on a bipartisan basis, so that their findings will be respected by all. Congressional commissions typically are invested with broad legal powers to carry out investigations, compel departments and agencies to provide any and all relevant information, hold hearings to air all points of view, and to conduct research. Congressional commissions endeavor to arrive at a consensus that can serve as the best-informed basis for public policy.

The EMP Commission had all of the above powers and characteristics, not least in that the EMP Commissioners and staff included our nation’s foremost experts on EMP, nuclear weapons, and critical infrastructures. For example, the EMP Commission Chairman, Dr. William Graham, began his career working on EMP at the Air Force Weapons Laboratory (AFWL), then Rand Corporation and later R&D Associates, and later served as President Reagan’s Science Advisor. EMP Commissioner Dr. John Foster is our nation’s foremost nuclear weapons expert, having worked on the design of most of the nuclear weapons in the current US inventory. Other EMP Commissioners and staff have equally impressive backgrounds as nationally recognized experts on the national power grid, telecommunications and other critical infrastructures, and on testing and modeling to assess their vulnerability. The EMP Commission has excellent bipartisan credentials, having been first established by a Republican-majority Congress, re-established by a Democratic-majority Congress, with all commissioners selected on a bipartisan basis. The EMP Commission conducted groundbreaking experiments, some never before attempted, using EMP simulators to test a wide variety of electronic systems, vital to operation of critical infrastructures, in order to assess their vulnerability to EMP. Eight years of the most comprehensive and meticulous investigation and research yet conducted on the vulnerability of modern critical infrastructures went into the EMP Commission’s threat assessment. Collaborating with the EMP Commission’s work and reviewing its reports were the Intelligence Community (CIA, DIA, NSA); the military services (US Strategic Command, Air Force, Army, and Navy); the National Nuclear Security Administration laboratories (Lawrence Livermore, Los Alamos, and Sandia); the Department of Defense and the Department of Homeland Security.2

Given this background on the EMP Commission, the vast resources available to it, the scale and duration of its work, and the vast extent of its collaboration and review, does it really seem plausible, as Dr. Butt suggests, that the EMP Commission erred, or lied, about the nuclear EMP threat that could be posed by terrorists and rogue states?

EMP threat from low-yield nuclear weapons

Dr. Butt’s chief argument against the EMP Commission is his unfounded assertion that EMP from a low-yield (1-kiloton) nuclear weapon—that he assumes would be the yield of a terrorist or rogue state nuclear weapon—is not sufficient to cause catastrophic consequences against US critical infrastructures. Dr. Butt hinges his argument on the well-known fact that, for nuclear weapons of conventional design, a weapon of high yield will produce stronger EMP fields than a weapon of low yield. But this does not prove—and nowhere does Dr. Butt prove or offer compelling evidence—that EMP from a low-yield nuclear weapon would be insufficient to cause a national catastrophe.

It must be noted that Dr. Butt’s assumption that a terrorist or rogue state nuclear weapon could not have a yield greater than 1-kiloton is a view unique to him, and constitutes an unrealistically benign assessment of the likely nuclear threat. Proliferation of a Russian tactical nuclear weapon—of which there are many thousands, being the most numerous nuclear weapons in the world—is still considered one of the most likely pathways by which terrorists or rogue states might acquire a nuclear weapon. Russian tactical nuclear weapons typically have yields of 10-100 kilotons, and can be up to a megaton.3

But let us first deal with Dr. Butt’s argument on its own terms, and consider his extraordinarily benign EMP scenario, clearly a “strawman” constructed by Dr. Butt to support his hypothesis, where the threat is from a 1-kiloton weapon.

Tellingly, unable to offer or find test results or calculations that support his dismissal of the EMP threat from low yield weapons, Dr. Butt complains that the EMP Commission unclassified report does not divulge test data for the EMP effects of nuclear weapons of varying yield. Dr. Butt:

Although the EMP commission carried out tests of the robustness of various devices to E1, the unclassified version of the commission documents do not contain many meaningful technical details. We simply do not know the level of EMP stress applied in the quoted tests, and whether they would be appropriate to a large (greater than 100 kilotons) or a small (1 kiloton) type device.

Of course, the EMP Commission was not at liberty to disclose—and was careful not to disclose—classified data that could help terrorists or rogue states attack the American people. The EMP Commission deserves credit for sharing with the American people more unclassified information on the EMP threat to critical civilian infrastructures than ever before provided, an achievement that required the EMP Commission report to undergo several years of security review.

What of Dr. Butt’s questioning the EMP threat from a 1-kiloton nuclear weapon? Since the EMP Commission warns that any nuclear weapon, including a low yield nuclear weapon, could be used to make a catastrophic EMP attack on the United States, the reader can be confident that the EMP Commission’s test data supports that judgment.

The EMP Commission sponsored tests on commercial equipment and evaluated the failure levels of equipment separately from the computation of the E1 and E3 HEMP fields for different weapons and scenarios. The EMP Commission could not openly publish the results of detailed HEMP calculations for specific weapon designs, but it was clear that there would be significant effects from all types of weapons. As expected, the area coverage of larger yield weapons for E3 HEMP is larger than from lower yield weapons.

However, Dr. Butt is mistaken in suggesting that HEMP effects are somehow linearly scalable with weapon yield, especially for E1 HEMP. Yield is more of a factor for E3 HEMP, but there is a saturation effect for E3 (and E1) HEMP, and the maximum fields on the ground do not scale with total yield. Consequently, the E3 HEMP field from a 10-kiloton weapon is not 100 times smaller than for a 1-megaton weapon. It should be noted that the IEC maximum specification for E3 HEMP is 40 V/km. A field of 1 V/km is enough to create serious effects on a power grid.

Dr. Butt’s statement that “significant E3 would not be expected from a low yield weapon, as would be expected from a solar storm” is misleading. It is true that a “great” geomagnetic storm could produce larger E3-like fields on the ground than a low yield weapon, but such a storm produces “overkill.” The E3-like fields produced during the Hydro-Quebec blackout in 1989 can also be produced by a low yield weapon.

Even Dr. Butt’s own calculations, biased to minimize the threat, indicate that EMP from a 1-kiloton weapon would be significant, a fact Dr. Butt reluctantly acknowledges and tries to obfuscate rhetorically. Dr. Butt:

The bottom line is that, indeed, our infrastructure is vulnerable to significant E1 and E3 pulses… while a small weapon could certainly produce substantial destructive E1 fields, such fields would be restricted to only a small region of the country… Serious long-lasting consequences of a one-kiloton EMP strike would likely be limited to a state-sized region of the country.

Most Americans would regard the loss to EMP of an entire state to be non-trivial. Moreover, everything we know about the response of the electric grid to accidental failures and natural disasters indicates a propensity for small local problems to escalate and spread over much wider areas, and for the resulting widespread blackout to cause cascading failures in other critical infrastructures. This is so because the national electric grid is aged and often operating on the verge of failure—and everything depends upon electricity. It would be “suicidally optimistic,” to borrow a phrase from Dr. Butt, to assume that an EMP attack that inflicted a state-wide blackout would not also cause cascading grid and infrastructure failures at least regionally. Indeed, such an event could well become a protracted national blackout.

Dr. Butt’s calculations are deliberately biased to limit the EMP effects by first selecting a threat yield of 1-kiloton, and then claiming effects “only” in one state. He argues that terrorists or rogue states using a 1-kiloton weapon would want to optimize the EMP field strength by detonating at the lowest possible altitude, trading a gain in increased EMP field strength for a greatly reduced area of effect, limited to a radius on the ground of 725 kilometers. Dr. Butt:

…the “sweet spot” for maximizing the EMP lethality of such weapons would be a detonation altitude of about 40 kilometers--significantly higher, or lower, and the peak fields at ground level will decrease....For 40 kilometers altitude, the maximum extent of the induced EMP E1-fields is within a 725-kilometer radius.

However, contrary to Dr. Butt, terrorists or rogue states may prefer to trade reduced EMP field strength for a gain in area coverage, detonating their low-yield nuclear weapon at a higher altitude, covering the eastern part of the United States with an EMP field. Dr. Butt is mistaken that only the maximum region of the E1 HEMP field is important. That is completely wrong, as the peak electric field is not the only important parameter for coupling to cables and equipment. Extensive research has found that more horizontal angles of incidence of the E1 HEMP are much more efficient in coupling to lines, despite their lower field strengths. The many errors in Dr. Butt’s understanding of HEMP phenomenology appear to result from a lack of familiarity with some of the most basic texts on EMP, such as E.F. Vance’s Coupling to Shielded Cables and MIL-STD-188-125, which provides a method of hardening and testing ground-based C4I facilities to HEMP. The MIL-STD-464 cited by Dr. Butt as a source is recognized among specialists as having little value for EMP aspects.

EMP from a 1-kiloton weapon, though “weak” in comparison to a megaton-range EMP, could still have catastrophic consequences for the critical infrastructures that sustain the U.S. economy and society. This is so because the US electrical power grid, which supports all the other critical infrastructures, is extremely fragile and vulnerable to any EMP attack. Modern microelectronics are over one million times more vulnerable to EMP than electronic systems of the 1960s, and could be damaged or destroyed by the EMP from a low-yield nuclear weapon detonated high enough to cover, for example, the eastern United States. Safety relays and SCADAs (System Control And Data Acquisition) control everything, including the current flowing into big transformers that are indispensable to the power grid, and that currently would require years to be repaired or replaced.4 Dr. Butt himself provides anecdotal evidence illustrating the shocking fragility of the electric power grid, citing the August 2003 Northeast Blackout and the cascading failures that resulted when a high voltage power line was assaulted by a tree branch:

The outage affected the Northeast US and parts of Canada and more than 200 power plants, including several nuclear plants, were shut down as a result of the electricity cutoff. Other effects included loss of water pressure, possible sewage contamination, gridlock, various other transportation problems (because of secondary effects on railways, airlines, and gas stations), and disruption of oil refineries’ operations. Phone service was stressed due to high call volume and several radio and television stations went off the air. It is estimated that the one-day blackout cost $7–10 billion in spoiled food, lost production, overtime wages, and other related expenses inflicted on more than one-seventh of the US population.

All of this from a tree branch. It is not an isolated incident. The EMP Commission found many large-scale blackouts of the power grid that were started by a seemingly trivial local problem.4 A low-yield nuclear weapon detonated to place an EMP field over the entire eastern portion of the United States would certainly place more stress on the electric grid than a single tree branch, and multiply the above effects manifold by causing many local failures, that could cascade into a national catastrophe.

Sophistication of rogue state and terrorist nuclear weapons

Dr. Butt is fixated on disproving the EMP threat from a 1-kiloton nuclear weapon because he mistakenly thinks the EMP Commission shares his assumption that this is the likely yield for a rogue state or terrorist nuclear weapon. According to Dr. Butt:

…such missiles [as Iran’s Shahab-3] have a payload capacity of approximately 1,000 kilograms corresponding to a crude U-based warhead of 1 kiloton yield—if, and when, the Iranians eventually develop nuclear weapons. Even the North Koreans, who are much further along in their weapons program, have had great difficulty reaching even a 5 kiloton yield from their Pu-based devices in carefully orchestrated ground tests, and their 2009 test was likely a fizzle.

The historical record and the best evidence does not support Dr. Butt’s view that terrorist or rogue state nuclear weapons are likely to be inferior to the first atomic bombs produced by the United States during World War II. If terrorists get a nuclear weapon, most analysts believe it will come from Russia or one of the rogue states, and so be far more sophisticated than anything the terrorists could build themselves. Dr. Butt’s rosy views about nuclear proliferation notwithstanding, the Defense Department and State Department have given high priority and invested vast resources to prevent the proliferation of nuclear weapons and technology from Russia. The threat of nuclear proliferation from Russia is still very real, as President Obama made clear in his 2010 State of the Union Address.

Nuclear aspirant rogue states, like North Korea, Iran, and Syria, have a huge advantage over the United States’ Manhattan Project of World War II, which invented the first atomic bombs in three years relying on 1930s and 1940s era technology. Rogue states can draw upon huge quantities of unclassified and declassified literature—including the original Manhattan Project papers—for guidance on building their nuclear weapons.6 Rogue states can and do purchase on the international market all manner of commercial and dual-use technologies relevant to developing nuclear weapons, technologies 70 years more advanced than that available to the U.S. Manhattan Project. Rogue states can and do rely on international criminal organizations, like the A.Q. Khan network, to help them get the technology and know how they need for nuclear weapons. Rogue states help each others’ nuclear weapons programs, as North Korea was recently helping Syria, and is helping Iran.7 Rogue states can and do buy help from Russia and China.

The record does not support Dr. Butt’s assumption that rogue state nuclear weapons are likely to be primitive. Credible open source reporting, including from Mordecai Vanunu, who worked in Israel’s nuclear weapons program, indicates that Israel has developed an array of sophisticated nuclear weapons, including thermonuclear weapons and miniaturized warheads for its Jericho missile—without nuclear testing.8 There is no reason North Korea, Iran, and Syria cannot duplicate Israel’s feat, especially as they have even greater resources than Israel. Pakistan and India quickly leapt from a few nuclear tests to deployment of an array of nuclear weapons, including warheads miniaturized for delivery by ballistic missile. Pakistan claims to have tested a thermonuclear weapon. If true, it is less likely a high yield weapon, and more likely a specialized weapon, like a neutron bomb. Sam Cohen, “Father of the Neutron Bomb,” credited Israel and South Africa with developing such weapons.9 The United Nations nuclear watchdog, the IAEA, discovered that a criminal group proliferated blueprints for a miniaturized nuclear warhead that could be delivered by Iran’s Scud or Shahab-3 missiles.10

Super-EMP weapons

Last but not least, senior Russian EMP experts warned the EMP Commission that “brain drain” from Russia enabled North Korea to make what the Russians call “Super-EMP” weapons.11 According to Russian open sources, these are small, low-yield nuclear weapons that can generate extraordinarily powerful EMP fields, many times more powerful than the E1 EMP from a multi-megaton weapon.12 Both of North Korea’s nuclear weapons tests that produced low yield “fizzles” look very like what would be expected from a “Super-EMP” weapon. According to open source reporting, South Korean military intelligence claims North Korea is receiving Russian help developing “Super-EMP” weapons.13

Moreover, the EMP Commission discovered from its investigations that, as noted in the Commission’s unclassified Executive Report, “Certain types of relatively low-yield nuclear weapons can be employed to generate potentially catastrophic EMP effects over wide geographic areas, and designs for variants of such weapons may have been illicitly trafficked for a quarter-century.”14

On a related matter, Dr. Butt incorrectly asserts that “due to the fact that the super-EMP weapon will be directional, it is unlikely to effect a large part of the country.” In fact, a “Super-EMP” weapon can be designed to be directional (the more challenging design) or to cover broad area (the simpler design). The simplest design of a “Super-EMP” nuclear weapon, configured for broad area coverage, could generate extraordinarily high EMP fields over the entire contiguous United States.

The bottom line is that no one knows how sophisticated or unsophisticated present and future terrorist and rogue state nuclear weapons may be. But it would be folly to gamble the lives of millions of Americans on Dr. Butt’s unwarranted certainty that those weapons are and will remain unsophisticated.

Russia and China

Dr. Butt reassures us that the United States need not worry about any EMP threat from Russia or China, as these nations will be deterred by economic self-interest. Dr. Butt:

We owe China tremendous sums of money, they need us as a market, and both the US and China require Russian oil via intertwined world markets.

Those who opposed military preparedness before World Wars I and II used this same argument—that German aggression and world war was impossible because of the economic interdependence of European states and the world. Economic interdependence did not stop the world wars from happening. Nor did China’s economic partnership with the United States stop a Chinese general, during the 1996 Taiwan Straits Crisis, from threatening a nuclear strike against Los Angeles.15

While the United States no longer views Russia and China as enemies, the reverse is not also true. Russia and China in public statements and military writings continue to portray the US as a potential enemy, often as a reckless aggressor seeking to impose a New World Order dominated by the United States.16 Russian and Chinese military writings are replete with scenarios and references to making EMP attacks against the United States.17 Indeed, during the 1999 Balkans Crisis, leaders of the Russian Duma raised the specter of a Russian EMP attack that would paralyze the United States, in order to stop US bombing of Serbia.18 In 2009, shortly after the election of President Obama, Russian President Medvedev threatened to neutralize NATO’s deploying missile shield by targeting nuclear weapons on radars and interceptors in Poland and the Czech Republic, and by “radioelectronic means”—Russian parlance for EMP.19

The EMP Commission Report warns, “China and Russia have considered limited nuclear attack options that, unlike their Cold War plans, employ EMP as the primary or sole means of attack.”20 America cannot afford to bet its security on the perpetual good will of Russia and China. Deterrence of an EMP attack on the United States by Russia or China only has to fail once for the American people to suffer catastrophic consequences.

ICBM EMP threat

Dr. Butt asserts: “A state would be highly unlikely to launch an EMP strike from their own territory because the rocket could be traced to the country of origin and would probably result in nuclear or massive conventional retaliation by the US.” Contrary to Dr. Butt, if the EMP attack works, the United States will be in no condition to retaliate. Russian open source military writings claim that “Super-EMP” weapons generate such powerful fields that even hardened U.S. strategic forces would be vulnerable.21 Massive conventional retaliation by the United States, which could deter such an attack, depends on the survival of US civilian critical infrastructures that are indispensable to power projection.

Moreover, if retaliation is possible, there is the dilemma of what kind of nuclear retaliatory strike the United States would make in response to an EMP attack? The EMP targets electronics, not people, and would not immediately kill millions. Mass casualties would come later, from secondary effects, if the United States continues to be unprepared. A retaliatory EMP strike on a nation like North Korea would be close to meaningless, since they are not as dependent as the U.S. on advanced electronic infrastructures. Inflicting a nuclear holocaust on Tehran or Pyongyang for an EMP attack might not seem like a proportionate response to an American president, at least not immediately.

Further, nations like North Korea and Iran may seek long-range missiles so they can credibly threaten to launch an EMP attack from their territory, rather than actually execute such an attack. The acquisition of such capability will immediately change the calculus of risk for the United States in upholding its alliance relationships, and in US willingness to impose sanctions or undertake military action against the state capable of launching an EMP attack against the American homeland. Rogue states that possess a “force in being” capable of threatening the American homeland with EMP would have a promising means of deterring the United States. During the Cold War, the United States deployed hundreds of missiles and thousands of warheads to establish a Mutual Assured Destruction (MAD) relationship with the Soviet Union, that successfully deterred the USSR from invading NATO or attacking the United States. Today, with one or a few ICBMs capable of inflicting a catastrophic EMP attack on the American people, a rogue state could recreate the MAD relationship with the United States, very much to the detriment of American interests.

Finally, vengeance should not be underestimated as a motive for a rogue state launching an EMP strike from its own territory against the United States. North Korea and Iran and other rogues are probably doomed for the ash heap of history. When they collapse, if they can take their enemies with them, they will almost certainly try to do so. Rogue leaders will want the United States to know that the EMP attack came from them, when the mob is at their gate.

Nuclear terrorism

One scenario of particular concern to the EMP Commission is that rogue states or terrorists could make an “anonymous EMP attack” by launching a short- or medium-range missile off a freighter outside US territorial waters.22 This would eliminate the need for an ICBM to deliver the EMP attack. Since the EMP strike would come from no one’s territory, it could also conceal the identity of the attacker. Although it would not be necessary, an additional layer of anonymity could be achieved by a state sponsor by contracting with terrorists to carry out the attack.

Dr. Butt contends “it is highly unlikely that a nation would give one of its crown jewels [a nuclear weapon] to an unpredictable terrorist cell.” Dr. Butt quotes a paper done at the National Defense University that states, “Iran would not, as a matter of state policy, give up control of such weapons to terrorist organizations and risk direct U.S. or Israeli retribution.”23

Yet Iran and Syria are killing Americans and Israelis every day, by providing increasingly sophisticated weapons to Hezbollah and Hamas to attack Israel, and to terrorists in Iraq to kill Americans there, apparently without fear of US or Israeli retribution.

Dr. Butt’s view that not even Iran—the world’s leading sponsor of international terrorism—would give a nuclear weapon to terrorists, is an opinion unique to Dr. Butt and the authors of the NDU paper, which does not represent the official view of the National Defense University. The mainstream view, so widely held that it probably deserves to be described as a consensus, is that Iran, North Korea, Russian organized crime, or other actors might transfer a nuclear weapon to terrorists. Iran’s sponsorship of international terrorism is one of the chief reasons successive American presidents have made it a priority of their administrations to stop Iran’s nuclear weapons program. In hearings held before the Senate Homeland Security Committee in 2008, Chairman Joseph Lieberman and the Director of Intelligence for the Department of Homeland Security, Mr. Charlie Allen, both warned that state-sponsored nuclear terrorism is a real prospect.24 That is why one of the most ambitious programs sponsored by the Department of Homeland Security is to improve U.S. port security and develop new technologies capable of detecting a nuclear weapon being smuggled into a US city.

The consensus view of the Congressional Commission on Weapons of Mass Destruction (reporting in 2008 and 2010), whose findings—like that of all Commissions—are supposed to provide the authoritative basis for making national security policy, warns that state-sponsored nuclear terrorism is a very real threat.25 The consensus view of the Congressional Commission on the Strategic Posture of the United States (reporting May 2009), independently arrived at the same conclusion as the EMP Commission, and warns that “the United States should take steps to reduce the vulnerability of the nation and the military to attacks with weapons designed to produce electromagnetic pulse (EMP) effects… The homeland might be attacked by terrorists or even by state actors with an eye to crippling the U.S. economy and American society.”26

page 2: shipborne “anonymous” EMP attack >>


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