A warning about a prolonged U.S. power outage has brought renewed attention to electricity-grid security. But the alarming suggestion of an 18-month nationwide blackout needs context: it comes from a scenario discussed more than a decade ago, rather than a prediction that such an event is imminent.

Jon Wellinghoff, former chairman of the Federal Energy Regulatory Commission (FERC), described the concerns in reporting by The New York Times Magazine. His account connected an analysis of grid vulnerabilities with the 2013 attack on Pacific Gas and Electric’s Metcalf substation near San Jose, California. According to that reporting, he warned federal officials that extensive transformer losses could cause an exceptionally prolonged outage.

The distinction between a possible scenario and an expected event matters. A warning about what could happen under extreme conditions does not establish how likely those conditions are—or demonstrate that the same outcome would occur on today’s grid.

The Metcalf attack nevertheless had a lasting influence on electricity-security policy. FERC has identified the incident as the event that prompted the development of a dedicated physical-security reliability standard.

In November 2014, FERC approved the standard, known as CIP-014-1. It required covered transmission owners to identify facilities whose loss could cause widespread instability or cascading failures, assess threats, and develop and implement security plans. The requirements also included independent verification of risk assessments, making the process more than an internal utility review.

Subsequent incidents have shown why those protections remain important. In December 2022, attacks on two substations in Moore County, North Carolina, caused approximately 45,000 customer outages. That month, FERC outlined a review of whether the physical-security standard needed improvements, including whether its coverage and assessment requirements were adequate.

Wellinghoff’s warning raises a serious question about preparedness, but the historical analysis alone cannot establish the probability or duration of a future nationwide outage. Readers should therefore treat the 18-month claim as an attributed extreme scenario, with substantial uncertainty—not as evidence that the United States is about to lose electricity for more than a year.

The practical issue is how effectively utilities can prevent major damage and restore service when infrastructure fails. That question deserves scrutiny without presenting a worst-case estimate as an inevitable outcome.