Electromagnetic Pulse: The Dangerous but Overlooked Threat

A nuclear electromagnetic pulse (EMP) event could wipe out the U.S. power grid—and along with it satellite ground stations, financial markets, healthcare systems, transportation networks, military command and control systems, and the technologies Americans rely on.

What is an EMP event? In layperson’s terms, a man-made EMP event, probably an attack, would use the “pulse” from a nuclear explosion high in the atmosphere to damage or destroy vulnerable electronics over a vast area.

The natural form of EMP, a solar storm, can wreak similar havoc. The Canadian province of Quebec experienced a 12-hour blackout in 1989 due to a solar flare. Schools, businesses, and transit systems were shut down.

Systems controlling the power grid are particularly vulnerable, but hardly alone. The electromagnetic radiation from a targeted, high-altitude EMP (HEMP) attack delivered via missile could disrupt most microelectronic-based and online systems within the HEMP footprint—from cell towers to car computers.

Whereas an area impacted by a solar storm can recover with help from nearby, unaffected utilities and communities, full restoration could take years following a continent-wide, multi-EMP attack due to lack of assistance from contiguous regions.

“We could have very dangerous scenarios across the country,” says John Trovato, a nuclear effects expert and a MITRE representative on the Electromagnetic Defense Task Force (EDTF).

Some claim, and past reports and studies indicate, that an EMP event could disrupt key activities like banking, shopping for groceries, buying gas for generators, and even driving a car. Clean water could become scarce. Hospital generators could run out of power, with outages lasting several weeks or more. Public panic and, ultimately, loss of life could follow.

Can the U.S. do more to mitigate the EMP threat posed by near peer and rogue nation-states? Or be better prepared for the next geomagnetic disturbance, which some experts predict at 25 percent probability in the next 25 years?

Yes, according to MITRE’s EMP subject matter experts: Trovato, Greg Robertshaw, Raul Blanche, Mike Cohen, and Nick Donnangelo. Combined, these experts bring deep experience in electromagnetic and nuclear effects, physics, applied mathematics, phased-array antennas, test and evaluation, cybersecurity, and intelligence analysis. 

Needed: A Whole-of-Nation Plan

Robertshaw notes that the first nuclear weapon test in 1945 produced EMP, so the threat isn’t new. It has, however, been on and off the national radar for decades, at times dismissed as overhyped or outdated.

“We relaxed about this threat after the Cold War,” he says. “Our enemies didn’t.”

Foreign military writings include EMP attack as part of information warfare tactics, as reflected in expert Congressional testimony and EMP Commission reports, Robertshaw adds.

Through the years, experts on all sides—including former U.S. defense secretaries William J. Perry and the late James R. Schlesinger, first EMP Commission director William R. Graham, executive director of  the task force on National and Homeland Security and former EMP Commission chief of staff Peter Vincent Pry, and former director of the Strategic Defense Initiative Organization Amb. Henry Cooper—have sounded the alarm about the U.S.’ vulnerability to attack by EMP weapons. Many agencies and commissions, the EDTF, the Congressional EMP Commission and others, have examined the threat.

In 2019, the White House issued an executive order—Coordinating National Resilience to Electromagnetic Pulses—to shed more light on the threat and determine courses of action.

Awareness of EMP is building on Capitol Hill. The House and Senate versions of the FY21 National Defense Authorization Act include pending provisions calling for the Department of Defense to report on EMP-related threat scenarios and harden strategic deterrent ground-based weapons systems, respectively.

These are encouraging steps, yet what’s needed is a whole-of-nation plan to mitigate the EMP threat.

Old Threat, New Paradigm 

Unlike a large nuclear weapons exchange, where retaliatory attacks would threaten all nations and citizens (mutually assured destruction, or MAD), according to Robertshaw, “HEMP effects leverage the geomagnetic field to achieve extremely wide-area destruction … without radioactively poisoning the earth’s inhabitants and ecosystems.”

In other words, by using multiple high-altitude nuclear explosions “a winnable nuclear war is possible,” Robertshaw says, “in bold contrast to the MAD doctrine.”

Blanche adds, “An effective HEMP attack may use only a few warheads and does not require the reentry vehicles to penetrate the atmosphere, a technical challenge for some adversaries today.”

An adversary might also see such an attack as being of lower risk than a direct attack upon the United States. If no one is directly killed by a HEMP attack, would the U.S. respond with the same force as it would to a direct military assault?

Fixes Within Reach

The steps needed to prevent an EMP catastrophe are well understood. First, mitigate known vulnerabilities in the country’s power grid. Next, fortify or harden the nation’s critical commercial infrastructure and stockpile necessary long lead time components like transformers.

A priority is protecting high-voltage transformers of the power distribution system with neutral line blockers. That is, block destructive quasi-DC currents induced by an EMP.

In an important step on this front, MITRE filed a patent application in August for a novel approach to detect and mitigate disturbances along the grid. The approach will offer another method to reduce the grid’s vulnerability to a HEMP attack or a geomagnetic storm.

“Power grid fixes are feasible and relatively reasonable in cost,” Cohen says. “And there are several approaches.”

The Foundation for Resilient Societies estimated a comprehensive fix at $50 billion. This is a significant amount of money, but it compares to annual U.S. electric industry revenues of $406 billion in 2018.

The Gemunder Center estimates it would cost $1.5 billion to harden the power grid’s 2,500 most critical transformers.

A more gradual, lower-cost approach is to begin by adding neutral ground blockers to the country’s nine most vital transformer substations. This option would require less than $1 billion investment, per a 2019 assessment, led by Robertshaw, of HEMP’s potential impact and recommended mitigations.  

If grid components are left unprotected, MITRE estimates a successful HEMP attack on the northeastern and midwest portions of the U.S. grid could cause $1.3 trillion in societal damage, nationally. This estimate was calculated and extrapolated using a U.S. computable general macroeconomic model based on a threat scenario of a four-month cyberattack-induced blackout in the northeast U.S.

Another vulnerability? The fast-growing U.S. constellation of low-earth-orbit (LEO) satellites.

“The EMP Commission and others predict that even a limited HEMP attack could destroy unhardened LEO satellites,” Blanche says.

Because LEO satellites operate at altitudes from 500 to 2000 km, while HEMP occurs at the 300 to 500 km range, the same HEMP event that would impact the power grid could disable LEO satellites that provide weather, telecommunications, military functions, and other vital systems.

An adversary could position a LEO satellite to deliver a targeted HEMP attack on command. Such an attack could neutralize satellites critical to U.S. military operations.

Partnering with Government to Assess the Threat

Like all national security threats, EMP is constantly evolving. Whether by a HEMP attack or a solar coronal mass ejection, the U.S.’ critical infrastructure and federal continuity could potentially be disrupted. As such, the Department of Homeland Security’s National Risk Management Center requested that MITRE conduct an updated, impartial, national-level critical infrastructure risk assessment. Cohen is leading the evaluation of possible impacts and outcomes from an EMP event.

“In coordination with DHS and the Federal Emergency Management Agency, we’re also developing an EMP operational test and evaluation plan for the National Public Warning System,” Cohen says.

This work supports the quadrennial EMP risk assessment’s requirement to incorporate vulnerability test plans. (See Electromagnetic Pulse (EMP) Program Status Report, August 2020.)

The team members note that MITRE is uniquely situated to convene and lead the critical public interest discussion about the EMP threat.

“We understand the technical side, the standards aspect, the policy side, and the economic impact,” Trovato says. “By looking at the EMP threat from all angles, we can evaluate potential outcomes, identify viable solutions, and as a neutral entity, help implement them through strategic public-private partnerships.”

Competing National Priorities

The EMP threat and proposed solutions are competing for attention and resources with far more tangible, immediate national priorities such as the coronavirus pandemic; economic, military, and ideological challenges of the Great Power Competition; and widespread protests for racial and social justice.

“Americans are largely unaware of EMP or its potential consequences,” Trovato says. “We need to get the public’s attention and give people the tools to make basic preparations. There’s a balance between being a ‘prepper’ and being equipped to meet short-term needs.”

It will take government officials, privately and publicly owned utilities, industry, the scientific community, and citizens working together to define the scale and scope of the EMP threat, develop a comprehensive, cross-sector strategy, and secure the funding needed to implement standardized, widescale mitigations.

—by Karina Wright