Carolina Journal Radio listeners might remember a recent program which featured highlights from former CIA Director James Woolsey’s remarks to a state legislative committee. Woolsey urged lawmakers to take steps to help protect North Carolina’s electrical grid from the harmful impacts of an “electromagnetic pulse.”

The latest issue of Hillsdale College’s Imprimis tackles the same topic. Claremont Institute President Brian Kennedy mentions EMP threats during a discussion of the need to boost national security.

America’s electrical grid is vulnerable not only to San Jose-style attacks, but to an electro-magnetic pulse (EMP) attack—a nuclear explosion in the high atmosphere, creating an electro-magnetic pulse that destroys electrical wiring and hardware across the affected area. Such an explosion placed over the center of the U.S. could destroy the infrastructure that distributes electricity to consumers and industrial users in every state except Alaska and Hawaii. This phenomenon has been well understood since the 1960s, and Cold War–era nuclear strategy assumed that a nuclear attack on population centers would be accompanied by an EMP attack in order to disable an enemy’s command and control system.

As a side note, it has recently been discovered that a massive solar storm could cause similar damage—although probably less extensive. Scientists estimate that such storms, called Coronal Mass Ejections, strike the earth every 150 to 300 years. Since the advent of electricity we have not experienced this type of event, which means we are in the window—indeed, it is believed that such a storm just missed Earth last July. At a 2013 conference to assess such risks, analysts from Lloyds of London concluded that “the total US population at risk of extended power outage from a [Coronal Mass Ejection] is between 20 to 40 million, with durations of 16 days to 1-2 years.”

Why is it important to be thinking about the possibility of terrorists waging coordinated San Jose-style attacks on large transformers—maybe the San Jose attack was a practice run, after all—or of an EMP attack, or of a solar storm of the kind just described? What we know from work performed in the 1990s by a Congressionally-mandated EMP Commission is that without electricity, the U.S. has the industrial infrastructure to provide for only 30 million of its over 300 million citizens.