Critical undersea infrastructure CUI as these connections are known, supports about US9-trillion worth of trade per day. A coordinated attack on this network could undoubtedly have devastating consequences.
But, as a former submarine commander who researches maritime security, I believe that attacking and disrupting the network is not as easy as some reports might make it appear. Deliberately snagging a pipeline with a dragging anchor in relatively shallow waters can cause a lot of damage, but it is a fairly indiscriminate trick with a shelf life, since the damage can be repaired, and deniability becomes increasingly difficult.
Targeting the cable networks in deeper waters require more sophisticated methods, which are much more challenging to carry out.
A hostile state wishing to attack this network first needs to locate the cables they wish to target. Most of the newer commercial cables are very clearly charted, but their positions are not exact.
Cables and pipelines, even the heaviest ones, will drift somewhat as they are laid, and the deeper the water they sit in, the greater the distance they may drift.