Angst over a potential electromagnetic pulse attack bubbles up every few months, and it’s easy to understand why. The EMP impact envisioned by people who have studied it closely would be downright apocalyptic: a decimated US power grid, and up to 90 percent of Americans dead within a year. It doesn’t help, either, that North Korea recently invoked the specter of an EMP attack, and seems increasingly like it would have the wherewithal to pull one off.
In broad strokes, if you explode a nuclear weapon at high altitude, it generates an electromagnetic pulse, which in turn can disrupt electronics ranging from cars, to street lights, to the US power grid itself. By what degree depends on whom you ask.
Scary stuff, especially that 90 percent number, which was first offered by representative Roscoe Bartlett in a 2008 Congressional hearing, and backed by a physicist—and leading voice in the EMP issue—named William Graham. But Bartlett himself sourced the figure from a work of science fiction, William R. Fostchen’s One Second After. And while an EMP surge, be it from a hydrogen bomb detonated high above North America or powerful solar storm, would surely impact daily life, the extent of the possible repercussions remains uncertain. At least where North Korea is concerned, that lack of an assured outcome should help ease—if not totally erase—EMP concerns.
Blackout or Bust
It’s important to note early that the EMP threat has become an unlikely live wire. Its most extreme proponents genuinely fear near-total annihilation; its vocal detractors dismiss the threat as science fiction.
In between, though, lie some important subtleties. Crucially, you won’t find much disagreement on the very basic science. In fact, both the US and Russia have proven this out in practice. In 1962, the US conducted a nuclear test known as Starfish Prime, in which it detonated a 1.4 megaton nuclear warhead 240 miles above the Pacific. The resulting EMP knocked out hundreds of street lights, and some telephone communications, 900 miles away in Hawaii. Russian tests at around the same time, over Kazakhstan, reportedly resulted in an EMP that took out a 300-mile communication line, among other assorted impacts. Evidence persists beyond those specific corollaries as well.
“You don’t need to do high-altitude nuclear tests to know the EMP threat is real,” says Dr. Peter Pry, who served on the Congressional EMP Commission and has published several books about its potential impacts. Pry points to data gleaned from underground nuclear tests and EMP simulators, all of which, he says, indicate the strong potential for devastation.
“I’m sure you’ve had the experience of driving a car down the road, listening to the radio, and then you’ve driven under a high power line, and suddenly your radio doesn’t work. You come out the other side and it works again. What’s happened is you’ve passed through an electromagnetic field that upset your radio,” says Pry. “I don’t think you have to be Albert Einstein to realize that if that electromagnetic field were, say, a billion times more powerful, that your radio would not just be upset but it would be destroyed, the electronics in your car destroyed. Imagine that now not being a localized phenomenon, but extended to the whole North American continent.”
‘I don’t know how the proponents of EMP get such huge results. I just don’t follow their logic.’
PHILIP COYLE, CENTER FOR ARMS CONTROL AND NON-PROLIFERATION
The commission Pry served on—tasked with investigating the threat—laid out that case in a 200-plus page 2008 report, and Pry himself speaks passionately on the topic. But EMP skeptics still abound, particularly in the North Korean context. And the EMP Commission shut down on September 30, after the Department of Defense and Department of Homeland Security didn’t seek funds from Congress to continue its operation.
“The fact that North Korea has tested a larger yield nuclear weapon than before is of concern because of the yield of the nuclear weapon, not because of EMP,” says Philip Coyle, a senior science fellow at the Center for Arms Control and Non-Proliferation, who served as the Assistant Secretary of Defense and Director of Operational Test and Evaluation at the Pentagon, and spent decades studying nuclear weapons at Lawrence Livermore National Laboratory.
Coyle acknowledges that EMPs can be a problem—the electromagnetic pulse from an 1859 solar storm, known as the Carrington Event, would have devastating consequences if repeated today—but he and others remain skeptical as to the true impact of the type of nuclear-based attack outlined by the EMP Commission.
“I don’t know how the proponents of EMP get such huge results. I just don’t follow their logic,” says Coyle. “There just isn’t a scientific basis to get these huge results, these huge numbers.”
“There’s still not proof that it would destroy a wide area of electrical equipment today,” says Sharon Burke, who served as Assistant Secretary of Defense for Operational Energy in the Obama administration and is currently a senior adviser at the New America Foundation, a non-partisan think tank. “There’s no actual proof that this would happen.”
Pry dismisses those who regard EMP as science fiction as “idiot naysayers.” But Coyle, Burke, and others who have raised doubts don’t deny the underlying scientific principals. “Nuclear weapons do put out electromagnetic pulses of different varieties, and some of them are quite dangerous,” Burke says. “You’ll find that a lot of US military equipment, at least from the Cold War, was shielded against those kinds of EMPs.”
For EMP threat skeptics, though, decades-old tests and modern simulations don’t equal a guaranteed result today. Which means the right question to ask isn’t if North Korea could explode a nuclear weapon high over the United States. It’s whether Kim Jong Un would take that risk, uncertain of the ultimate effect, but knowing that his country would receive the full weight of American military response in return.
Or, as Burke puts it: “If you’re a country that wants to go to war with the United States, and you want to cause maximum damage, you want to be pretty sure it’s going to work.”
North Korea attacking the US with an EMP would be a fantastically high-risk maneuver, with uncertain gains. And even if it did incapacitate much of the US power grid, it wouldn’t prevent a counterstrike. US military equipment is hardened, and its response could come from plenty of places other than North America.
In fact, even testing the effects of an EMP attack could provoke US military engagement, says Bruce Bennett, who specializes in asymmetric threats at the Rand Corporation.
“The North Korean foreign minister recently threatened to detonate a nuclear weapon over the Pacific to demonstrate their missile capabilities. I think if he even does that, not as EMP, there is a fairly significant chance that the US would respond,” says Bennett.
That sort of provocation would be out of character for Kim Jong Un, who despite the public bluster has historically known where the boundaries are, and managed not to cross them. His main objective is the survival of his regime; exploding a nuclear weapon above the United States would almost certainly assure its destruction.
‘If you’re a country that wants to go to war with the United States, and you want to cause maximum damage, you want to be pretty sure it’s going to work.’
SHARON BURKE, NEW AMERICA
Given all the uncertainty, the takeaways about the EMP threat are also unclear. Long-term investment in hardening US grid infrastructure makes some sense, but headlines blaring that North Korea could kill 90 percent of the US population with one EMP strike seem counterproductive.
“The threat of nuclear weapons and nuclear war with North Korea is a plenty big enough threat as far as I’m concerned,” says Coyle. “Talking about EMP, I think it’s just a distraction. I don’t know why it keeps coming up.”
As often happens, the best course to chart might be somewhere down the middle.
“The threat is perhaps best characterized as low probability but potentially very high consequence,” says Frank Cilluffo, director of George Washington University’s Center for Cyber and Homeland Security. “For this reason, the prudent course is to prepare in advance,” through international cooperation to try and contain North Korea, and an increased focus on preventative measures at home and in space.
Pry disagrees. In recent Congressional testimony, he offered perhaps the cleanest distillation of the EMP argument, in that it’s equal parts irrefutable and unprovable.
“I suspect people will continue to describe an EMP threat as unlikely,” said Pry, “right up until the day before North Korea actually attacks us.”