Tapping undersea cables used to be a thing, but these days, encryption is extremely cheap; tapping cables can only work if the owner of the cable is negligent.

Tapping undersea cables used to be a thing, but these days, encryption is extremely cheap; tapping cables can only work if the owner of the cable is negligent. And if the cable isn't encrypted properly, updating the equipment on both ends is much cheaper than running a new cable. (Installing devices to enable quickly cutting cables during a crisis, on the other hand, is something that would work and that they might plausibly be doing.)