EMP Pearl Harbor?EMP threat to U.S. should be kept in perspective

Published 10 September 2010

In 1962 the United States conducted a high-altitude nuclear test above Johnston Island, 825 miles southwest of Hawaii; detonated 400 kilometers above the island, the resulting nuclear blast knocked out street lights across Hawaii and tripped circuit breakers, triggered burglar alarms, and damaged a telecommunications relay facility on the island of Kauai; could terrorist, or a nuclear-armed rogue state, launch an EMP Pearl Harbor against the United States?

EMP knocks out power in a wide area // Source: propagandamatrix.com

In late 1962 — a year before the Partial Test Ban Treaty went into effect, prohibiting its signatories from conducting aboveground test detonations and ending atmospheric tests — scientists were surprised by the high-altitude electromagnetic pulse (HEMP) effect. During a July 1962 atmospheric nuclear test called Starfish Prime, which took place 400 kilometers above Johnston Island in the Pacific, electrical and electronic systems were damaged in Hawaii, some 1,400 kilometers away. The Starfish Prime test was not designed to study HEMP, and the effect on Hawaii, which was so far from ground zero, startled U.S. scientists.

High-altitude nuclear testing effectively ended before the parameters and effects of HEMP were well understood. The limited body of knowledge that was gained from these tests remains a highly classified matter in both the United States and Russia. Consequently, it is difficult to speak intelligently about EMP or publicly debate the precise nature of its effects in the open-source arena.

The limited practical experience with EMP has not stopped the debate about it — and what should the United States do to prepare for it. In early August a scientist warned that DHS has not taken seriously the threat that high-altitude detonation of a nuclear weapon could fry the U.S. power grid. The physicist, Dr. Michael J. Frankel, warned the Judiciary Subcommittee on Terrorism and Homeland Security that a terrorist organization or a rogue state could detonate a nuclear weapon either above the United States or close to its shores, creating an electromagnetic pulse attack that could severely damage the country’s electronic infrastructure. Frankel is executive director of the EMP Commission, which was created in 2001 to study the national security threat an EMP attack could pose to the United States. While most of its work is classified, the commission has released two unclassified reports: one in 2004 (.pdf) and another in 2008 (.pdf) (“How serious is the threat of an ‘EMP Pearl Harbor’?” 9 August 2010 HSNW).

Stratfor’s Scott Stewart and Nate Hughes write that there is little doubt that efforts by the United States to harden infrastructure against EMP — and its ability to manage critical infrastructure manually in the event of an EMP attack — have been eroded in recent decades as the cold war ended and the threat of nuclear conflict with Russia lessened. This is also true of the U.S. military, which has