News of North Korea’s latest nuclear development, which appears to be a hydrogen bomb estimated to be five to ten times more powerful than any previous nuclear ordnance North Korea possessed, has sent shockwaves around the world.  No longer does Kim merely possess the destructive power of an atom bomb, he now has a thermonuclear city killer – but in all sincerity, that may be the least of our worries.

One of the byproducts of a nuclear reaction is the release of a powerful electromagnetic pulse.  That pulse overloads the circuits inside non-hardened electronic devices, knocking out the power and often damaging those circuits beyond repair.  Of course, the subsequent power outage often goes unnoticed, as the residents of a targeted city try to dig themselves out from the irradiated rubble that was once their homes… but what if a thermonuclear weapon were to detonate high in the atmosphere above us?  Well, then we’re going to notice.

If Kim were to choose to attack the United States, an EMP-based attack would likely be the better option, over a direct nuclear strike.  Concerns about the survival of North Korea’s re-entry vehicles could be mitigated by detonating higher in the atmosphere, and while one thermonuclear warhead could feasibly wipe out the majority of a city, the same warhead could also potentially cripple a far larger swath of the nation.  Kim seems to be well aware of this, as North Korea’s announcement of a successful hydrogen bomb test came coupled with threats of an EMP attack.

So how exactly would such an attack unfold?  It would invariably start with the launch of one of North Korea’s long range ballistic missiles, likely their most successful platform to date, the Hwasong-14 (which goes by the U.S. designation KN-20).  In fact, in order to successfully pull off this attack, North Korea would need to launch a volley of such missiles, as a large percentage of them would likely be intercepted long before they could reach the skies above the U.S.

THAAD emplacements in South Korea would immediately identify the launch and begin calculating a trajectory, as would Aegis missile defense platforms aboard both U.S. and Japanese naval vessels.  Depending on the trajectory employed by the ICBMs, THAAD launchers in Kodiak, Alaska could also be called on to engage these missiles as they sailed high over the Pacific.  In all likelihood, a North Korean ICBM attack on the mainland United States would end there, as interceptors ranging from kinetic impactors launched by the THAAD to traditional SM-6s launched by ships could be employed in the intercept effort.

However, if one or more long-range, thermonuclear tipped missiles were to slip through the two layers of protection provided by THAAD and Aegis systems, the missiles would still have to get past America’s troubled, but competent, Ground-based Midcourse Defense system, or GMD.  Because the GMD’s track record is spotty, the United States would likely launch as many as five interceptors at each inbound ICBM, ensuring at least one of them would successfully destroy the missile somewhere along its flight path.  This strategy would prove effective, unless North Korea somehow managed to field enough missiles to overwhelm all three layers of missile protection.

Unlikely as it may seem that a North Korean missile could get past each of these advanced defensive systems, a number of variables could improve their chances.  Launching a huge number of missiles at once, aimed at targets locally as well as the mainland, could suffice to overwhelm the equipment, or personnel, tasked with manning the THAAD and Aegis systems, leaving only the GMD to hopefully accomplish the intercept.  Unforeseen circumstances could also improve their chances at victory, as depicted in the recent dogfight between a Navy F/A-18 Super Hornet and a comparably outmatched Syrian SU-22 in the skies over Syria.  The Super Hornet first fired the most advanced air-to-air missile platform we have, the AIM-9X Sidewinder, at the SU-22 and missed.  The old jet’s flares were outdated and dirty, which allowed them to successfully fool the missile designed to outsmart the flare systems employed by the latest in enemy fighters.  In short, American gear may prove less effective against North Korean missiles than against our own test-platforms, and there’s really no way to know until we attempt to engage one.

Thus far, everything about this method of attack mirrors a traditional nuclear strike in every way, but the real difference comes from re-entry.  Instead of the missile needing to make it all the way to a surface city (or slightly above the surface), it would only need to detonate above the atmosphere.  The result would be an immediate, and mostly permanent, power loss for as much as 75% of the entire nation.

A power outage caused by an EMP, however, would be nothing like any outage most Americans have ever seen before.  Not only would the lights go out, but as frantic Americans reached for their flashlights and cell phones, they would find those too no longer functioned.  Cars wouldn’t start.  Generators wouldn’t power up.  Emergency radios would be useless.  There would be no transportation, no communication, and no help on the way.

The recent outpouring of support and downright heroism demonstrated by people in and around the areas of Texas hardest hit by Hurricane Harvey provide an excellent example of how Americans can come together to help those in need, but in the days following an EMP attack, such a sense of community would be unlikely.  Without any way to communicate important information to the populous, the majority of the population would begin to grow uneasy within hours, and potentially unruly within days, but those would be the lucky ones.

Anyone reliant on medical care for survival would likely die rapidly, as hospitals and similar medical facilities were crippled by a lack of power.  Grocery stores would no longer be getting shipments of goods, nor would any form of refrigeration function.  Fresh drinking water would become a dangerously scarce commodity in many places, as faucets would fail to turn on without electric pumps and modern filtration methods.  Throughout much of the country, power would be the first to go, but it would be taking water, food, medical care, and any motorized means of transportation with it.

Now, it is entirely likely that some equipment would simply power down, and not suffer sufficient damage to prevent it from coming back online with a new power source – but even these vehicles would soon prove useless, as fuel pumps failed to work, and no new shipments of fuel ever arrived.

“Except for certain critical military assets, existing lightning protection, and some pilot hardening against GMD threats, critical national infrastructure remains largely unprotected from EMP threats,” the Department of Energy explained in a 2017 report.  “EMPs would likely impact many of the consumer and commercial electronics powered by the grid, and these also would be affected simultaneously in an EMP event.”

The U.S. government employs hardened assets at various places throughout the country, and may even be able to maintain a small semblance of internal communications, but mass communication to the public would remain nearly impossible.  Riots, looting, and violence in the streets would begin out of fear and frustration, but continue and grow as people became increasingly desperate.  The world outside the United States may continue to function, but in many ways, an EMP attack would seem like the end of the world for those in the affected zone – and for all intents and purposes, they would be right.

In much of America, life would become a twisted version of the Old West, with no electricity to speak of, and far too large a population to support with the resources at hand.  Some communities would fair better than others, but, with the exception of the noble efforts of some in the immediate aftermath of the attack, it seems unlikely that there would be much resembling law enforcement or emergency responders as people began to shift their focus toward their own family’s survival, rather than the well-being of the community at large.

Cities would be the worst hit.  Modern metropolises rely on imported goods to support their massive populations, and without a steady stream of supplies, people would grow desperate quickly.  Human desperation coupled with a lack of first responders and the general proximity of such large numbers of people would create a perfect storm for violence and mass panic.

In those early days following an EMP attack, North Korea would not need to kill any Americans with their missiles.  Our modern reliance on power would kill the first wave, and it’s entirely likely that fighting amongst ourselves would kill many more.

Image courtesy of the Department of Energy