It could be the early days of a new Cold War for the digital century.
President Barack Obama on Thursday announced sweeping sanctions against Russia in response to the country's cyberattacks in recent months.
Obama had promised action after federal investigators determined Russia had conducted hacking operations to interfere with the 2016 presidential election. The attacks included accessing emails from the Democratic National Committee, Democratic presidential nominee Hillary Clinton and her campaign manager, John Podesta.
"All Americans should be alarmed by Russia's actions," Obama said in a statement. "These data theft and disclosure activities could only have been directed by the highest levels of the Russian government."
The charges of election meddling represent an escalation of tense relations between the two superpowers. Russia and the US squared off through decades after the end of World War II that were marked by the buildup of nuclear arsenals, showdowns in proxy nations, and shadowy use of human and high-tech surveillance.
In recent years, the advent of digital technologies -- not least the internet -- has led to new forms of confrontation and skulduggery. That includes hacking of government and business operations.
A spokesman for Russian President Vladimir Putin said that Russia will consider retaliatory measures of its own, according to the Associated Press. Russia's embassy in the United Kingdom responded to the sanctions with a tweet calling Obama a lame duck.
Russia has consistently denied any involvement in hacking directed toward the US elections.
In October, the Department of Homeland Security and the National Intelligence Office pointed the finger at Russia, saying that "such activity is not new to Moscow -- the Russians have used similar tactics and techniques ... to influence public opinion there."
On Thursday, the DHS and the FBI expanded on that October joint statement, describing "malicious cyberactivity" by Russian intelligence services encompassed under the name Grizzly Steppe. They released a report documenting technical details of the methods used to "compromise and exploit" networks associated with the US election and with other government, political and private sector entities.
Thursday's actions come amid Obama's last month in office. On January 20, Donald Trump will be sworn in as the 45th president of the US. Trump has expressed skepticism about Russian cyberattacks and influence on the US election.
Speaker of the House Paul Ryan said in a statement Thursday that the sanctions were "overdue."
"Russia does not share America's interests. In fact, it has consistently sought to undermine them, sowing dangerous instability around the world," Ryan said.
On Thursday, Obama issued an executive order that gives US agencies more authority for responding to cyberattacks. He also sanctioned Russia's two intelligence agencies, four intelligence officers and three companies that helped in the cyberoperations.
Belan is accused of hacking at least three major US e-commerce companies, where he stole more than 200 million accounts and sold the private information. Bogachev is accused of developing and selling the Zeus malware, as well as creating Cryptolocker, a ransomware program behind 120,000 hacks that stole more than $100 million from US financial institutions and government agencies.
In addition, the US State Department shut down two Russian compounds, in Maryland and New York, along with kicking out the 35 Russian diplomats who worked there.
The FBI and the Department of Homeland Security plans to release declassified information on Russia's civilian and military intelligence cyberactivities, to help prevent Russia from striking other nations with cyberattacks.
Obama has promised more actions against Russia, some of which will not be made public. The US Cyber Command, an agency with ties to the NSA and the US military, has the potential to launch a counteroffensive as part of the US's retaliation.
The White House said it will also provide Congress with a full report on Russia's cyberattacks in the coming days.
The president ordered a full report on cyberattacks and foreign intervention during the election, setting the deadline for January 20.
Updated at 12:32 p.m. PT: To include more details on the Russian hackers sanctioned in the US's response.