By Nathan Hodge

MOSCOW -- The sanctions imposed by Washington on Moscow's top intelligence services has sharpened the focus on the links between Russia's security services and the world of black-hat hacking.

The Kremlin, which has consistently denied any government involvement in the cyberattacks, promised a retaliation. Though it isn't clear whether the Russians will respond with tit-for-tat diplomatic expulsions, Russian officials have repeatedly said they would have no other response to such measures by the U.S.

"Tomorrow there will be official statements, countermeasures and much more," Russian Foreign Ministry spokeswoman Maria Zakharova said Thursday.

The U.S. measuresalso stand to test the limit of sanctions: The U.S. and Europe originally imposed sanctions in 2014 to punish Russia economically for the annexation of the Black Sea peninsula of Crimea from Ukraine, but the Kremlin now predicts a return to growth in 2017 -- and is counting on a new administration in Washington that may move to end them entirely.

Kremlin spokesman Dmitry Peskov told reporters that the White House had two aims: "to ruin once and for all Russian-American relations, which were already at rock bottom and, apparently, to strike a blow against the foreign-policy plans of the future administration and the new U.S. president."

Russian President Vladimir Putin, Mr. Peskov added, would formulate Russia's reaction. "The principle of reciprocity applies here absolutely without alternative," he said.

The steady drumbeat of hacking revelations over the past year has prompted serious concerns about high-end Russian capabilities for hacking, with calls growing on Capitol Hill for a fuller probe of the Kremlin's involvement in electronic intrusions of the Democratic National Committee and the email account of Hillary Clinton's campaign chairman , John Podesta.

Russia has long had a rich talent pool of scientific and technical expertise, a legacy of Cold War-era competition between the U.S. and the Soviet Union. The U.S. spent heavily on so-called threat-reduction programs designed in part to provide work to scientists who were once part of the Soviet nuclear-weapons complex -- and to keep them from selling their expertise abroad.

But those institutes established to serve the military-industrial complex have created a large pool of freelancers with expertise in cryptography, mathematics and physics, experts say.

Technical universities "have special relations with the security services, because they were built to support the military-industrial complex," said Andrei Soldatov, an expert on Russia's efforts to control the internet. The graduates "all had respect for security services and narrow technical educations."

After the annexation of Crimea, he said, Russia's IT industry wasn't in a position to turn down requests from the security services. "They have been extremely loyal," he said. "If you are asked to provide some help in most cases you would say yes. You have a large community of people in the IT industry who are ready to answer the call."

The bulk of hacking that originates in Russia is carried out for criminal -- not political -- ends, cybersecurity experts say. A 2015 report on Russian financial cybercrime by Kaspersky Lab said law-enforcement agencies from a number of different countries, including the U.S., Russia, Belarus, Ukraine and European Union nations arrested more than 160 Russian-speaking cybercriminals who belonged to small, medium-size and large criminal groups between 2012 and 2015. Calls to the Russia's Federal Security Service, one of the main targets of the U.S. sanctions, weren't returned.

The allegations have also raised questions about the effectiveness of Western efforts to change Russian behavior.

Russia's economy has seen two years of negative economic growth, a result both of sanctions and the drop in global prices for oil, Russia's main export. The Russian government now predicts that the recession will end in 2017, in part as oil prices recover.

But some critics of the Obama administration say the sanctions, softer than those imposed on Iran for its nuclear program, have thus far been insufficiently strong. "While today's action by the administration is overdue, it is an appropriate way to end eight years of failed policy with Russia," House Speaker Paul Ryan (R., Wis) said Thursday.

The EU also imposed several rounds of sanctions on Moscow since 2014, but Russian officials now openly talk of hopes that EU members -- uncertain and divided after the U.K.'s Brexit vote -- will eventually lose the resolve to keep renewing them.

More important for Russia, a new administration is taking office in Washington that is expected to be more Moscow-friendly. President-elect Donald Trump has spoken of his high regard for Mr. Putin, and Russian officials expect a possible sea change in U.S. relations after his inauguration.

With that in mind, Moscow fired a parting shot at the Obama administration over the new sanctions. The foreign ministry's Ms. Zakharova said in a Facebook post that the White House had been occupied for two terms by "a group of foreign-policy losers, angry and short-sighted. Obama admitted it officially today."

--James Marson and Olga Razumovskaya in Moscow contributed to this article.

Write to Nathan Hodge at nathan.hodge@wsj.com

(END) Dow Jones Newswires

December 29,2016 20:14 ET (01:14 GMT)

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