The weapons earmarked for the struggle include submarines, underwater drones, robots and specialized ships and divers. The new battlefield is also a gray legal zone: Current Law of the Sea conventions cover some aspects of undersea cables but not hostile acts.
There’s evidence that missions are already under way and that most big powers, including the US, are keen on engaging in such activities. Cables can also be attacked by terrorists and other non-state actors.
The damage from such hard-to-detect acts could be enormous, since a foe’s economy, in addition to military and diplomatic communications, could be blinded. As more nations exploit the Internet for political or military gain, it’s also clear that the tactical concept of undersea cables as critical assets to be attacked or defended is an idea whose time has come.
"In the most severe scenario of an all-out attack upon undersea cable infrastructure by a hostile actor the impact of connectivity loss is potentially catastrophic, but even relatively limited sabotage has the potential to cause significant economic disruption and damage," a former commander of the North Atlantic Treaty Organization, retired US Navy Admiral James Stavridis, wrote in the foreword to a recent report, "Undersea Cables: Indispensable, Insecure."
...
US intelligence officials contend that Russia is the chief offender in the new cable war. They have publicly disclosed that Russian submarines are "aggressively operating" near the Atlantic cables that serve the US mainland, as part of an asymmetric-warfare approach.
However, there are signs that the United States may be engaging in similar activities. In September, the US media reported that the USS Jimmy Carter, a Seawolf-class nuclear submarine equipped for intelligence missions, had returned to its base in Washington state flying a Jolly Roger pirate flag beside the US flag.
Continues at link.