WASHINGTON — President Obama struck back at Russia on Thursday for its efforts to influence the 2016 election, ejecting 35 suspected Russian intelligence operatives from the United States and imposing sanctions on Russia’s two leading intelligence services.
The administration also penalized four top officers of one of those services, the powerful military intelligence unit known as the G.R.U.
Intelligence agencies have concluded that the G.R.U. ordered the attacks on the Democratic National Committee and other political organizations, with the approval of the Kremlin, and ultimately enabled the publication of the emails it harvested to benefit Donald J. Trump’s campaign.
The expulsion of the 35 Russians, who the administration said were spies posing as diplomats and other officials, and their families was in response to the harassment of American diplomats in Russia, State Department officials said. It was unclear if they were involved in the hacking.
In addition, the State Department announced the closing of two waterfront estates — one in Glen Cove, N.Y., and another on Maryland’s Eastern Shore — that it said were used for Russian intelligence activities, although officials declined to say whether they were specifically used in the election-related hacks.
Taken together, the sweeping actions announced by the White House, the Treasury, the State Department and intelligence agencies on Thursday amount to the strongest American response yet to a state-sponsored cyberattack. They also appeared intended to box in President-elect Trump, who will now have to decide whether to lift the sanctions on Russian intelligence agencies when he takes office next month.
Mr. Trump responded to the Russian sanctions late Thursday by reiterating a call to “move on.” But he pledged to meet with intelligence officials, who have concluded that the Russian hacking was an attempt to tip the election to Mr. Trump.
In an earlier statement from Hawaii, Mr. Obama took a subtle dig at Mr. Trump, who has consistently cast doubt on the intelligence showing that the Russian government was deeply involved in the hacking. “All Americans should be alarmed by Russia’s actions,” Mr. Obama said, and added that the United States acted after “repeated private and public warnings that we have issued to the Russian government, and are a necessary and appropriate response to efforts to harm U.S. interests in violation of established international norms of behavior.”
He issued a new executive order that allows him, and his successors, to retaliate for efforts to influence elections in the United States or those of “allies and partners,” a clear reference to concern that Russia’s next target may be Germany and France. Already there are reports of influence operations in both.
Mr. Trump’s position is at odds with most members of his party, who after classified briefings have called for investigations into the combination of cyberattacks and old-style information warfare used in the 2016 campaign. Mr. Trump has largely stuck to the theory he set forth in a debate with Hillary Clinton in September, when he said the hacks could have been organized by “somebody sitting on their bed that weighs 400 pounds.”
Russia criticized the sanctions and vowed retaliation.
“Such steps of the U.S. administration that has three weeks left to work are aimed at two things: to further harm Russian-American ties, which are at a low point as it is, as well as, obviously, deal a blow on the foreign policy plans of the incoming administration of the president-elect,” Dmitri S. Peskov, the spokesman for President Vladimir V. Putin, told reporters.
Konstantin Kosachyov, the head of the foreign affairs committee in the upper house of the Russian Parliament, told Interfax that “this is the agony not even of ‘lame ducks,’ but of ‘political corpses.’”
Despite the international fallout and political repercussions surrounding the announcement, it is not clear how much effect the sanctions will have, except on the ousted diplomats, who have until midday Sunday to leave the country. G.R.U. officials rarely travel to the United States, or keep assets here.
The four Russian intelligence officials are Igor Valentinovich Korobov, the chief of the G.R.U., and three deputies: Sergey Aleksandrovich Gizunov, Igor Olegovich Kostyukov and Vladimir Stepanovich Alexseyev.
The administration also put sanctions on three companies and organizations that it said supported the hacking operations: the Special Technology Center, a signals intelligence operation in St. Petersburg, Russia; a firm called Zorsecurity that is also known as Esage Lab; and the Autonomous Noncommercial Organization Professional Association of Designers of Data Processing Systems, whose lengthy name, American officials said, was cover for a group that provided special training for the hacking.
Still, the sanctions go well beyond the modest sanctions imposed against North Korea for its attack on Sony Pictures Entertainment two years ago, which Mr. Obama said at the time was an effort to repress free speech — a somewhat crude comedy, called “The Interview,” imagining a C.I.A. plot to assassinate Kim Jung-un, the country’s leader.
The sanctions are not as biting as previous ones in which the United States and its Western allies took aim at broad sectors of the Russian economy and blacklisted dozens of people, some of them close friends of Mr. Putin’s. Those sanctions were in response to the Russian annexation of Crimea and its activities to destabilize Ukraine. Mr. Trump suggested in an interview with The New York Times this year that he believed those sanctions were useless, and left open the possibility he might lift them.
The F.B.I. and the Department of Homeland Security on Thursday also released samples of malware and other indicators of Russian cyberactivity, including network addresses of computers commonly used by the Russians to start attacks. But the evidence in a report, in which the administration referred to the Russian cyberactivity as Grizzly Steppe, fell short of anything that would directly tie senior officers of the G.R.U. or the F.S.B., the other intelligence service, to a plan to influence the election.
A more detailed report on the intelligence, ordered by Mr. Obama, will be published in the next three weeks, though much of the information — especially evidence collected from “implants” in Russian computer systems, tapped conversations and spies — is expected to remain classified.
Several Obama administration officials, including Vice President Joseph R. Biden Jr., have suggested that there may also be a covert response, one that would be obvious to Mr. Putin but not to the public.
While that may prove satisfying, many outside experts have said that unless the public response is strong enough to impose a real cost on Mr. Putin, his government and his vast intelligence apparatus, it might not deter further activity.
“They are concerned about controlling retaliation,” said James A. Lewis, a cyberexpert at the Center for Strategic and International Studies in Washington.
But John P. Carlin, who recently left the administration as the chief of the Justice Department’s national security division, where he assembled cases against North Korean, Chinese and Iranian hackers, called the administration’s actions a “significant step that is consistent with a new model: When you violate norms of behavior in this space, we can figure out who did it and we can impose consequences.”
The Obama administration was riven for months by an internal debate about how much of its evidence to make public. In interviews for a New York Times investigation into the hack, several of Mr. Obama’s top aides expressed regret that they had not made evidence public earlier, or reacted more strongly. None said they believed it would have affected the outcome of the election, however.
In recent weeks, Mr. Obama decided that the authorities he created in April 2015 to retaliate against states or individuals that conduct hacking after the Sony attack did not go far enough. They made no provision issuing sanctions in response to an incursion on the electoral system — an attack few saw coming.
So he ordered his lawyers to amend the executive order, specifically giving himself and his successor the authority to issue travel bans and asset freezes on those who “tamper with, alter, or cause a misappropriation of information, with a purpose or effect of interfering with or undermining election processes or institutions.”
The administration has not publicly criticized how its own officials handled the case. But the Times investigation revealed that the F.B.I. first informed the Democratic National Committee that it saw evidence that the committee’s email systems had been hacked in the fall of 2015. Months of fumbling and slow responses followed.
Mr. Obama said at a news conference that he was first notified early this summer. But one of his top aides met Russian officials in Geneva to complain about activity in April.
By the time the leadership of the committee woke up to what was happening, the G.R.U. had not only obtained emails through a hacking group that has been closely associated with it for years, but, investigators say, also allowed them to be published on a number of websites, including a newly created one called DC Leaks and the far more established WikiLeaks. Meanwhile, several states reported the “scanning” of their voter databases — which American intelligence agencies also attributed to Russian hackers. But there is no evidence, American officials said, that Russia sought to manipulate votes or voter rolls on Nov. 8.
Mr. Obama decided not to issue sanctions earlier for fear of Russian retaliation ahead of Election Day. Some of his aides now believe that was a mistake. But the president made clear before leaving for Hawaii that he planned to respond.