Threats from other countries to jamming technology

North Korea, backed by Russia, is using military jamming aggressively

South Korean civil aviation is particularly vulnerable to jamming because Incheon International Airport—which serves the greater Seoul metropolitan area—is close to the border with North Korea. Incheon is only 23 miles from the demilitarized zone. 49.2 million passengers passed through Incheon in 2015, making it one of the busiest airports in the world.

On Tuesday, U.S. officials said forces destroyed six GPS signal jammer devices inside Iraq. Langley said the strikes illustrated another of the inherent weaknesses of jamming systems: the radio signals given off by the equipment reveal the jammer’s location.

Four US officials told NBC News that Moscow was concerned that the US would retaliate for the attacks in rebel-held eastern Ghouta, so it began jamming the GPS systems of some smaller drones. American analysts first noticed the Russian military jamming drones in eastern Ukraine after the invasion of Crimea four years ago, Humphreys said. The jammers “had a pretty significant impact” on UN surveillance drones, which were grounded for days after gathering intelligence from the air.

Renuart did not say specifically that the drone jammer were part of a shipment of materials supplied by Russian companies to Iraq, but the United States repeatedly has expressed its concern that Russia is letting the materials slip through in violation of decade-old U.N. sanctions.

A space arms race of sorts is underway with weapons under development or in the arsenals of China, Russia and the U.S. Space weapons include satellite jammers, lasers and high-power microwave gun systems.

Experts say the biggest threats seen today are non-kinetic threats such as jamming of satellite-based capabilities such as GPS and communications. And the threat isn’t limited to space-faring countries since the satellite jamming technology is relatively inexpensive.

North Korea has previously used ground jammers, impacting both military and civilian aircraft and ships. Harrison said there’s evidence that insurgents in Afghanistan and Iraq also have used jamming.