How Pyongyang can plunge US into darkness?

Pyongyang's latest nuclear test, successfully completed on September 3, has rekindled concern over a hypothetical electromagnetic pulse (EMP) attack that North Korea can launch against the US, thereby neutralizing US electric networks, according to the Daily Mail.

The newspaper notes that after the recent test of a hydrogen bomb, the possibility of an EMP attack against the US was first mentioned and that "the pulse caused by a high-altitude explosion can sow chaos and destruction" to a "far worse" scale than the nuclear attack itself.

According to Pyongyang, it is "a multifunctional thermonuclear weapon with destructive power that can be detonated even at great heights in a superpower EMP attack."

The explosion of a thermonuclear bomb in US airspace would create an electromagnetic pulse wave in the country, which in turn would generate an overload of power and a blackout of the power grids in the mainland.

Former Central Intelligence Agency (CIA) chief James Woolsey warns that such an attack would leave hospitals, government and civilian organizations, as well as all kinds of infrastructure in the country without electricity. "I think it's the main and the most important and dangerous threat to the US," the official told the San Diego Union-Tribune newspaper last March.

"We would be in a world without food supplies, without water purification, without banking, without telecommunications and without medicine, all of which depends on electricity in one way or another," Woolsey recalled.

The higher the altitude at which the bomb will be detonated, the wider the effect of the EMP. For example, a 30-kilometer bomb over the center of the United States would affect the states of Kansas, Nebraska, and almost the entire population of South Dakota. The explosion at an altitude of 400 kilometers would be enough to wipe out almost all US electronics and affect even some territories in Canada and Mexico.

This altitude corresponds approximately to that of the International Space Station (ISS) orbit and other terrestrial satellites. Pyongyang has already shown that it can reach these altitudes with its satellite launches in 2012 and 2016, and several experts consider that these tests have tested the trajectory of a possible EMP attack.