The issue goes beyond old Cold War worries 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.
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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.
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What worries Pentagon planners most is that the Russians appear to be looking for vulnerabilities at much greater depths, where the cables are hard to monitor and breaks are hard to find and repair.