But it is far from clear that the administration’s new “name and shame” effort, along with criminal prosecutions and counterattacks on Russian cyberunits, is successfully deterring attacks. Members of the G.R.U. were indicted in 2018 by Robert S. Mueller III as part of his investigation into Russian election interference.

Yet the attack in Georgia took place last fall, a year later, and involved techniques that American officials have been studying to determine if they might be used against the United States in the coming election.

Neither the United States nor its allies released any evidence used to establish how they tied the attacks to the G.R.U. That made it easier for the Russian Foreign Ministry to deny that Moscow was behind the assault. “Russia did not plan and is not planning to interfere in Georgia’s internal affairs in any way,” said the deputy foreign minister, Andrey Rudenko, according to the news site RIA.

There could be any number of reasons the United States has not released evidence. It may have wanted to avoid revealing its sources and methods, including getting inside Russian networks — though in the G.R.U. indictment, it was clear the United States was reading text messages and other communications of the agency’s officers. Under a relatively new American strategy for countering cyberattacks, called “persistent engagement,” the National Security Agency and United States Cyber Command, its military partner, operate inside adversary networks.

For years, Russia has tormented neighboring countries with targeted cyberattacks, including orchestrating two blackouts in Ukraine and broad online assaults on Estonian institutions. There were cyberattacks on Georgia in 2008, as part of a hybrid action in which Russia took control of some Russian-speaking parts of the country. It retains that control today.

The United States never formally attributed the cyberelement of those attacks to Russia, though outside experts say it was all part of a unified military operation that, in retrospect, was a crude but effective foreshadowing of Russian operations to come.

Mr. Trump has never publicly called out Russia for its cyberoperations. During the 2016 presidential debates, he argued that it was impossible to determine where a cyberattack originated — though that is exactly what his intelligence agencies and the State Department did in the Georgia case on Thursday.