Russia has been investing heavily in its submarine fleet over the past decade and a half, restocking its fleet with more sophisticated and more capable boats that are more active than at any time since the Cold War.
That activity has worried Western officials, who have particular concern for what those subs might be doing around the undersea cables that link the US, Europe, and countries around the world, carrying 95% of communications and over $10 trillion in daily transactions.
Now the US government is targeting that undersea capability by putting sanctions on Russian firms and individuals that work with the country's powerful FSB, the security and intelligence agency sanctioned in 2016 for interfering in the US election that year.
The US is pursuing "an ongoing effort to counter malicious actors working at the behest of the Russian Federation and its military and intelligence units to increase Russia's offensive cyber capabilities," Treasury Secretary Steven Mnuchin said in a release. "The entities designated today have directly contributed to improving Russia's cyber and underwater capabilities through their work with the FSB."
The Treasury said the sanctions were in response to "malign and destabilizing cyber activities," like 2017's NotPetya cyberattack and cyber intrusions of the US energy grid, which could allow future attacks.
Among the firms sanctioned on June 11, 2018, was Divetechnoservices, which, since 2007, "has procured a variety of underwater equipment and diving systems for Russian government agencies, to include the FSB," the Treasury Department said.
"Further, in 2011, Divetechnoservices was awarded a contract to procure a submersible craft valued at $1.5 million for the FSB," according to the release.
'The 21st-century, underwater equivalent'
Undersea espionage is not new. In 1972, specially equipped US submarines tapped a Soviet communications line off Russia's Pacific coast as part of Operation Ivy Bells, which remained secret until information about it was leaked to the Soviets in the early 1980s.
One of the subs that took part, the now retired USS Parche, is the most decorated ship in the Navy, though most of its missions remain secret. The Navy currently operates the USS Jimmy Carter, an advanced Seawolf-class sub that's believed to be modified to tap undersea cables.
"Just as the Russians have specialized submarines for this, we do too," Magnus Nordenman, the director the Transatlantic Security Initiative at the Atlantic Council, said in an interview earlier this year, citing the Carter specifically. "And it's certainly something that we did during the Cold War too."
Russia's navy is smaller in numbers than its Cold War predecessor, but its subs have grown more sophisticated, departing from the previous approach of lots of ships of varying quality. "They are taking a page from our playbook, which is go for quality instead," Nordenman said.
In 2015, US officials said increased Russian undersea activity could have been efforts to locate those cables. At the end of 2017, Stuart Peach, then chief of the British defense staff, said the "vulnerability of the cables that criss-cross the seabeds" was "a new risk to our way of life."
US Navy Rear Adm. Andrew Lennon, commander of NATO's subs forces, said in December 2017, that Russian underwater activity around those cables appeared to be unprecedented and that Moscow "is clearly taking an interest in NATO and NATO nations' undersea infrastructure."
"Intercepting and disrupting the opponent's communications has sort of been part of warfare since the beginning of time," Nordenman said earlier this year. "And this is the 21st-century, underwater equivalent."
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