Could a North Korean EMP Attack on the U.S. Really Cause Mass Starvation and Societal Collapse?

Millions of lives could be lost through mass starvation, disease and societal collapse following a North Korean electromagnetic pulse (EMP) attack, according to the author of a congressional report.

Testifying before a Congressional Homeland Security subcommittee earlier in October, Peter Vincent Pry, a nuclear strategist formerly with the CIA, warned of the devastating effects an attack using an EMP warhead could have.

As chief of staff to the congressional EMP commission, Pry was one of the authors of the report.

In an interview with Forbes Monday, he reiterated the warning and explained that the warheads can explode without re-entering the atmosphere. Up to now, debate has focused on the danger to the U.S. from North Korean intercontinental ballistic missiles (ICBMs), with experts casting doubt over their capacity to re-enter the atmosphere and hit targets in the U.S. mainland.

Super EMPs are nuclear warheads designed to explode hundreds of kilometers above their targets, producing gamma rays which generate the kind of high-frequency electromagnetic pulses most damaging to electronic devices, according to the report.

Pry said that North Korea could conceal a device in a satellite and detonate it remotely via an encoded signal, or time a device to detonate on an ICBM or even when intercepted by U.S. missile defense systems.

Pry warned of the devastating consequences of such an attack.

"The U.S. can sustain a population of 320 million people only because of modern technology," he said. "An EMP that blacks out the electric grid for a year would [decimate] the critical infrastructure necessary to support such a large population," he said.

In the worst case scenario, food in supermarkets would be consumed within three days and within 30 days national food supply in regional warehouses would begin to spoil, he continued, leading to an estimated 90 percent of the population perishing from ensuing starvation, disease and societal collapse.

So how likely is the scenario which Pry warns of? According to some experts, not very.

Writing for 38 North in May, former Department of Defense and intelligence contractor Jack Liu described the threat from EMPs as "grossly overstated" and said North Korea had not developed nuclear warheads powerful enough to be effective.

"North Korea's nuclear tests have not yet demonstrated sufficient yield to cause damage to large areas through EMP. Moreover, with only a limited arsenal, it would not make sense for the North Koreans to conduct nuclear tests simply to develop EMP weapons," he wrote.

Other scientists argue that not enough tests have been conducted to establish where in the Earth's atmosphere an EMP detonation would be effective, making its use by North Korea highly unlikely.

Peter W. Singer, a strategist for the New America Foundation and expert on 21st century warfare, took issue with Pry's claims, describing them as the stuff of "science fiction."

"EMP is where the science fiction of fears does not cross with reality," he told Newsweek.

He said that EMP was discovered as a by-product of nuclear tests at the outset of the Cold War, but it remains largely untested.

"North Korea [and other nuclear powers] have not tested it, to know what would be the design, height, range, etc. to have the effect they want," he said.

"So, the scenario assumes North Korea would finally decide to attack the U.S., to risk a war in which its leadership would die, but do so in an utterly untested, unpredictable manner, as opposed to using a nuke in a way that they know works and would definitely have a catastrophic effect on the the U.S. That is a pretty big assumption, the kind made in cruddy novels, but less likely in reality.

"If you are worried about North Korea, worry about the actual and far more likely use of their nuclear weapons, missiles or conventional cannons, rather than the stuff of weak science fiction."

The EMP Commission though remains convinced that the threat from a North Korean EMP attack is real—with a primitive, low-yield nuclear weapon likely to cause enormous destruction to U.S. electronic infrastructure if detonated at height.

"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," the authors of a 2004 commission report wrote.

The commission closed on September 30, with former House Speaker Newt Gingrich, one of the strongest proponents of the threat from EMPs, telling Foreign Policy that the slow pace of appointments under the Trump administration made progress on the EMP threat impossible.

He said he did not fight the commission's closure as "people I trust who are very concerned [about the threat] thought that we needed a fresh start."