As the nuclear crisis with North Korea continues to heat up, Pyongyang declaring that U.S. strategic bomber exercises practicing preemptive strikes against the North have brought the sides to the brink of nuclear holocaust, press pundits are full of speculation about what a new Korean War might look like.

Overwhelmingly, press commentary and analysis low-balls the North Korean nuclear missile threat. Press reporting focuses on the unreliability of North Korean missiles.

Speculation is accepted as gospel that North Korea allegedly does not have a reentry vehicle capable of penetrating the atmosphere. They allegedly lack guidance systems accurate enough to strike a military target, or at intercontinental ranges, even a city.

Therefore, North Korea cannot deliver on its threats to make nuclear attacks on the U.S. and its allies, at least not for the present, or so the reassuring story goes.

Elsewhere I have addressed the likely gross underestimation of North Korean nuclear missile capabilities, as described above, prevailing in the mainstream media (see Dr. Peter Vincent Pry, "Underestimating The North Korean Nuclear Threat," Secure Freedom Quarterly, 2nd Quarter 2016).

Almost no one talks about North Korean capabilities to make an electromagnetic pulse (EMP) attack, except to ignorantly dismiss and belittle the possibility, as did National Public Radio (NPR) in an interview with EMP non-expert Jeffrey Lewis on April 27.

Yet, the very pundits who claim North Korea has not developed reentry vehicles or accurate guidance systems or sufficiently reliable missiles should be most concerned about EMP attack — which requires none of these.

An EMP attack entails detonating a nuclear weapon at high-altitude, above the atmosphere, so no reentry vehicle is necessary to penetrate the atmosphere and blast a city. The area of effect of an EMP is so enormous — a warhead detonated at an altitude of 30 kilometers will generate an EMP field on the ground having a radius of 600 kilometers — that an accurate guidance system is unnecessary.

And the mass destruction of electronics and blackout of electric grids over such a vast region would be so injurious that missile reliability matters little — only one nuclear missile needs to work to deliver an EMP attack against an entire nation.

Academics and press pundits, who typically know nothing about EMP, mistakenly assert that a high-yield megaton-class (1,000 kilotons) nuclear weapon is needed for an EMP attack, whereas North Korea’s most powerful test was between 20 to 30 kilotons. But a high-yield weapon is not necessary to make an EMP attack.

I am looking at an unclassified U.S. Government chart that shows a 10-kiloton warhead (the power of the Hiroshima A-Bomb) detonated at an altitude of 70 kilometers will generate an EMP field inflicting upset and damage on unprotected electronics.

The Congressional EMP Commission 2004 report criticized the Defense Department for increasing reliance on commercial-off-the-shelf technology unprotected from EMP, warning, "Our increasing dependence on advanced electronic systems results in the potential for an increased EMP vulnerability of our technologically advanced forces, and if unaddressed makes EMP employment by an adversary an attractive asymmetric option."

On April 30, South Korean officials told The Korea Times and YTN TV that North Korea’s test of a medium-range missile on April 29 was not a failure, as widely reported in the world press, because it was deliberately detonated at 72 kilometers altitude.

72 kilometers is the optimum burst height for a 10-Kt warhead making an EMP attack.

According to South Korean officials, "It’s believed the explosion was a test to develop a nuclear weapon different from existing ones." Japan’s Tetsuro Kosaka writes in Nikkei, "Pyongyang could be saying, 'We could launch an electromagnetic pulse (EMP) attack if things get really ugly.'"

The April 29 missile launch looks suspiciously like practice for an EMP attack. The missile was fired on a lofted trajectory, to maximize, not range, but climbing to high-altitude as quickly as possible, where it was successfully fused and detonated — testing everything but an actual nuclear warhead.

The missile was launched from near Pyongyang, North Korea’s capital, and detonated not far away, over North Korean territory. A nuclear warhead detonated at 72 kilometers altitude would generate an EMP field with a radius of about 930 kilometers, covering all of North and South Korea and reaching far out to sea.

North Korea’s threat to destroy the U.S. Carl Vinson aircraft carrier group may have in mind EMP attack.

This sounds like the "Gotterdammerung" scenario, discussed by the EMP Commission, where North Korea seeks to defeat an invasion of its territory by an EMP attack that covers most of the theater of operations, to paralyze or cripple U.S. and allied forces, that are far more dependent on advanced electronics and high-tech than North Korea.

Pyongyang, knowing the moment of the EMP attack, can protect its forces in tunnels and shelters and by turning-off systems.

North Korea may be reacting to the joint U.S.-South Korea Foal Eagle military exercises conducted in March and April that practiced invasion of the North to disarm its nuclear forces and decapitate Pyongyang’s political-military leaders.

North Korea’s nuclear threats are not mere bluster. We should tread carefully.

Peter Vincent Pry is executive director of the Task Force on National and Homeland Security. He served in the Congressional EMP Commission, the Congressional Strategic Posture Commission, the House Armed Services Committee, and the CIA. He is author of "Blackout Wars."