This is reported by The New York Times, Censor.NET informs.
The issue goes beyond old worries during the Cold War that the Russians would tap into the cables - a task American intelligence agencies also mastered decades ago. The alarm today is deeper: The ultimate Russian hack on the United States could involve severing the fiber-optic cables at some of their hardest-to-access locations to halt the instant communications on which the West's governments, economies and citizens have grown dependent.
American officials are secretive about what they are doing both to monitor the activity and to find ways to recover quickly if cables are cut. But more than a dozen officials confirmed in broad terms that it had become the source of significant attention in the Pentagon.
In private, however, commanders and intelligence officials are far more direct. They report that from the North Sea to Northeast Asia and even in waters closer to American shores, they are monitoring significantly increased Russian activity along the known routes of the cables, which carry the lifeblood of global electronic communications and commerce.
Just last month, the Russian spy ship Yantar, equipped with two self-propelled deep-sea submersible craft, cruised slowly off the East Coast of the United States on its way to Cuba - where one major cable lands near the American naval station at Guantánamo Bay. It was monitored constantly by American spy satellites, ships and planes. Navy officials said the Yantar and the submersible vehicles it can drop off its decks have the capability to cut cables miles down in the sea.