The North American Electric Power Reliability Corporation’s (NERC) latest test of the U.S. electrical grid left out an important component: testing the U.S.’s ability to withstand an electromagnetic pulse (EMP).

The purpose of the two-day test was to gauge the response and recovery times from physical and cyber-attack scenarios. Although NERC claimed the test was a success (results are not available until next spring), the test did not consider an EMP attack, for which the nation remains unprepared.

An EMP can result from a nuclear weapon detonated between 40 kilometers and 400 kilometers above the earth’s surface, creating a pulse that would disable all electronic devices and electrical infrastructure. Congress assessed an EMP to be such a threat that it created a congressional EMP commission to determine the impetus of this threat.

It is known that Russian scientists have helped North Korea develop an EMP weapon. Given the relevance of an EMP, NERC should have factored this into its test.

Congressman Trent Franks (R–AZ) considers an EMP as “the most significant short-term national security threat that faces our country today,” also highlighting a sobering statistic that “about 99%” of the U.S. military’s electricity comes from the vulnerable electric grid. This is a potential national security risk that needs to be addressed. If left unattended, the effects of an electrical blackout caused by an EMP would be devastating.

To ensure adequate reliability and response times to possible future attacks, the U.S. electrical grid needs to be annually stress tested against threat scenarios seen in the actual threat environment.

The U.S. should also work to prevent an EMP attack; make plans to prepare for, respond to, and recover from a possible EMP; secure electrical infrastructure from virtual and physical threats; and develop a comprehensive missile defense deployed to protect the U.S. and its interests from possible ballistic EMP threats.

John Collick is currently a member of the Young Leaders Program at The Heritage Foundation. For more information on interning at Heritage, please click here.