Rolling blackouts during the recent cold wave has raised concern about the reliability of our electricity grid, but the growing possibility of deliberate sabotage may be a bigger threat.

The first sign America’s electricity grid might have become a target occurred in 2013, when a marksman disabled an electricity substation south of San Jose with more than a hundred long-range shots reportedly from a .50-caliber rifle. This was no casual prank or random act of vandalism. It was clearly planned, and the damage required nearly a month to repair.

At the time the FBI downplayed the incident, saying publicly that it didn’t think it was terrorist-related.

The mystery deepened with a series of Christmas Day attacks this year on two electricity substations in Washington state that led to blackouts for thousands of customers. Local authorities thought the attack was perhaps part of a burglary — thieves sometimes target electric-utility facilities for their valuable copper and other materials with a high black-market value — but there was a telling detail in the news stories on the incident: The local utility had received prior warning of a possible attack from “federal law enforcement officials.”

Which federal law-enforcement officials might those be?

In January a Department of Homeland Security report concluded that “extremist groups” had developed “credible, specific plans” to attack the grid. The report didn’t single out any particular group or motivation, saying a spectrum of extreme ideologies could have embraced the cause. According to one estimate, there have been more than 100 attacks on the grid this year.

The FBI has a long history of monitoring and infiltrating extremist groups and understandably remains tight-lipped about which groups it has under active surveillance.

While the Biden administration is obsessed with “right-wing extremism,” one can’t help but speculate whether targeting the grid is the newest front in ecoterrorism. The FBI and other government agencies have long downplayed this possibility.

There is certainly a long precedent for this kind of “direct action” from eco-fanatics. Thirty years ago, Earth First made its bones driving spikes into trees with the deliberate attempt to thwart logging, even though tree-spikes often resulted in serious injuries to loggers when they used their chainsaws. Other ecoterrorist groups such as the Earth Liberation Front and Animal Liberation Front committed arson against ski resorts and slaughterhouses, with one conviction for a late-1990s attack occurring only last spring.

The steady rise of the climate-change obsession is already seeing irrational and destructive public stunts such as blocking road traffic and trains and throwing paint or food at artwork in museums while gluing hands and feet to walls or floors. These antics don’t do anything to reduce greenhouse-gas emissions. But crippling the grid would. If so, it would represent the coming to life of one of the classic texts of radical environmentalism, Edward Abbey’s 1975 novel “The Monkey Wrench Gang,” which advocated, among other direct actions, attacks on major energy infrastructure.

The founders of Earth First said Abbey’s novel was one of their inspirations. Is a new generation of “monkey-wrenchers” now on the scene? The FBI and other government bodies owe us more candor about what is going on.

Steven F. Hayward is a resident scholar at the Institute of Governmental Studies at UC Berkeley.