After Mr. Trump’s inauguration, Russian hackers kept escalating attacks.
Mr. Trump’s initial cyberteam decided to be far more public in calling out Russian activity. In early 2018, it named Russia as the country responsible for “the most destructive cyberattack in human history,” which paralyzed much of Ukraine and affected American companies including Merck and FedEx.
When General Nakasone took over both Cyber Command and the N.S.A. a year ago, his staff was assessing Russian hackings on targets that included the Wolf Creek Nuclear Operating Corporation, which runs a nuclear power plant near Burlington, Kan., as well as previously unreported attempts to infiltrate Nebraska Public Power District’s Cooper Nuclear Station, near Brownville. The hackers got into communications networks, but never took over control systems.
In August, General Nakasone used the new authority granted to Cyber Command by the secret presidential directive to overwhelm the computer systems at Russia’s Internet Research Agency — the group at the heart of the hacking during the 2016 election in the United States. It was one of four operations his so-called Russia Small Group organized around the midterm elections. Officials have talked publicly about those, though they have provided few details.
But the recent actions by the United States against the Russian power grids, whether as signals or potential offensive weapons, appear to have been conducted under the new congressional authorities.
As it games out the 2020 elections, Cyber Command has looked at the possibility that Russia might try selective power blackouts in key states, some officials said. For that, they said, they need a deterrent.
The question now is whether placing the equivalent of land mines in a foreign power network is the right way to deter Russia. While it parallels Cold War nuclear strategy, it also enshrines power grids as a legitimate target.
“We might have to risk taking some broken bones of our own from a counterresponse, just to show the world we’re not lying down and taking it,” said Robert P. Silvers, a partner at the law firm Paul Hastings and former Obama administration official. “Sometimes you have to take a bloody nose to not take a bullet in the head down the road.”