What is an electromagnetic attack?

The phrase “electromagnetic attack” can refer to different things, but in this context most likely refers to a high-altitude electromagnetic pulse generated when a nuclear weapon is detonated in space, about 30 kilometers above the Earth’s surface. Once the weapon is detonated, an electromagnetic pulse can travel to the Earth’s surface and disrupt a wide variety of technology systems from appliances to a nation’s electric grid. Some characteristics of an electromagnetic pulse are similar to disturbances caused by solar flares.

There are also smaller electromagnetic pulse weapons that are being developed, but they would be unlikely to cause a power outage as large as the one Venezuela experienced, experts said.

The term electromagnetic attack also can refer cryptography, or an attack where the perpetrator is seeking secret keys or passwords, but that’s more likely to be directed at portable electronic devices, not electric grids, said Shucheng Yu, an associate professor of electrical & computer engineering at Stevens Institute of Technology.

Has electromagnetic pulse technology ever been used?

In the 1962, during the Cold War, the U.S. detonated a nuclear weapon above the atmosphere over the Pacific Ocean, and the experiment — known as Starfish Prime — knocked out power to traffic lights and telecommunications in parts of Honolulu, illuminating the sky and even leading hotels to host viewing parties, according to news reports.

Russia conducted a series of “high-altitude nuclear bursts” in 1961 and 1962 to test electromagnetic pulse impacts over Kazakhstan and destroyed that country’s electrical grid, according to testimony to Congress from the Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack.