If North Korea detonated a nuclear device 200 kilometers above the Earth in order to create an electromagnetic pulse, would the U.S. counterstrike North Korea with conventional and perhaps nuclear weapons?
The answer had better be “hell yes.”
Everyone agrees: an EMP attack over or near U.S., Japanese, or South Korean territory is a physical attack that would wreak havoc with communications, the power grid, and civilian physical infrastructure.
This quip makes the point with bumper sticker clarity: “EMP kills EMS.”
American emergency medical systems, or EMS, depend on mobile communications to route EMS ambulances to accident sites and citizens in physical distress. An EMP attack would knock out a seizure victim’s cell phone, the county EMS communication center, and the communications on the EMS ambulance. It would likely fry all of the electronics on the vehicle. If the ambulance has an electronic microchip key and a fancy-superkeen electronic ignition button, it might not even start.
EMS also relies on GPS, or Global Positioning Satellite location system. An electromagnetic pulse would damage GPS receivers. An EMP’s fritzing electrons in space could impede satellite to ground signals in the area for days, even though GPS satellites orbit 22,500 miles above the Earth.
An EMP attack could damage the SCADA systems monitoring and controlling critical infrastructure such as dams, factories, water and sanitation systems, oil refineries, and natural gas pipelines.
In short, an EMP attack destroys the electronic neurons and sinews of modern society.
North Korea could choose another option for EMP, though. PJ Media contributor Charlie Martin asked me to consider the following “gray area” scenario:
What if a North Korean EMP is intended as a “demonstration”? Suppose the nuke explodes over the North Pacific in an area that, say, the geography- and technology-ignorant cable news talking heads swear is open water, thousands of miles from U.S. and Japanese territory? And they claim that the only danger at that point is Trump’s response?
The answer: a blast virtually anywhere in the atmosphere above the North Pacific would harm us.
Starfish Prime, the July 9, 1962, U.S. atmospheric nuclear test, showed that an EMP can have long-distance consequences. The U.S. detonated a 1.45 megaton device at an altitude of 400 kilometers near Johnston Island (about 1,500 kilometers from Honolulu). The blast’s EMP damaged Honolulu street lights and shut down microwave phone links.
Yes, it was a much larger weapon than 200 kilotons, and it produced minimal ground damage. But the blast may have damaged several satellites in low-earth orbit.
Find Alaska’s Aleutian Islands on a map, and note the location of the fishing port Dutch Harbor, which has a Coast Guard base. Also find Attu, way out west, about 1,900 kilometers from the Russian port of Petropavlovsk.
Now look south to the Hawaiian Islands. Note that it’s about 3,800 kilometers from Dutch Harbor to Honolulu. From the Big Island of Hawaii, the island chain sweeps 2,400 kilometers west to Kure Atoll. It’s uninhabited. But Midway, halfway between North America and Asia, is inhabited. It’s 2,850 kilometers from Midway to Attu. So 4,100 kilometers separate Midway and Tokyo.
A 150-to-200 kiloton blast, 200 kilometers above the Earth, could cause physical damage to civilian infrastructure within a 1,000 to 1,500 kilometer radius. So theoretically, there are a few areas in this zone where a North Korean blast might not cause physical damage to structures on U.S., Japanese, and Russian territory.
However, the sea isn’t empty and uninhabited. Ships ply the area, and most of them civilian.
And commercial aircraft fly above it.
North Korea’s “demonstration” EMP over the North Pacific, from the Equator to the Aleutians, is actually a physical attack — potentially on inhabited islands, but definitely on critical trade and transportation routes in the sea space. Moreover, sensors and communication systems in a region critical to North American strategic defense could be temporarily dazzled or even damaged.
That would make the demonstration an electronic area denial attack of a sort, an attack for which Pyongyang damn well better be made to pay.