Undersea cables n are more than a concern now a days because it provides more than 75% of the internet in America. Saying that it is a vital role in the internet consumption of America will not be wrong. The concern is that according to the recent reports of different magazines, Russian military is planning to destroy these undersea lines in order to give a serious damage to the American networking system. And if it happens then it would be a real setback for both, the people using the internet and also the military forces of the country and the marine forces. The biggest problem is that the location of these lines is not hidden and anybody can have easy access to them, reaching to them is not a big issue especially not a big issue for a force like Russia.
It is such an easy task that even a fisherman can go deep in the seas and cut the cables with some good equipment. The only way to get this one off is to have a tight security around the cables by the American submarines which is the only available option because these cables were established in 1980s and are being used till now. So it will require more money for the marine forces but it is the only option available.