Australian defence minister warns of growing undersea cable sabotage threat

More than 95% of global internet traffic travels through an estimated 550 undersea fibre‑optic cables spanning over a million kilometres. Damage to these cables occurs on average every two days, caused by anchors, fishing gear, natural events and deliberate sabotage.

At the Shangri‑La Dialogue in Singapore, Australian defence minister Richard Marles highlighted an unprecedented rise in sabotage incidents over the past 18 months, describing the seabed as a "battlefield". He cited recent cuts in the Baltic Sea, the Taiwan Strait and near Vietnam’s coast. In 2023 all five international cables serving Vietnam were damaged almost simultaneously, reducing the country’s bandwidth to about 25% and forcing traffic onto slower land and satellite links for months.

Seventeen states have pledged to tighten protection of critical underwater infrastructure. Attribution remains difficult; Russia and China have been blamed for some incidents, but proof is scarce. The strategic rivalry between the United States and China further complicates repair work, as companies often need Chinese permits to access cables in the South China Sea, a region also contested by six Southeast Asian nations.