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. The expulsion of the 35 Russians, whom 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 Donald J. 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.