"They Can Be Cut by an Anchor at Night": Australia Warns of Undersea Cable Threat to Internet

Australia has highlighted the vulnerability of its undersea internet infrastructure, warning that damage to submarine cables could disrupt the communications systems carrying almost all of the country's international internet traffic.

According to a statement shared by the U.S. Embassy in Australia, approximately 99% of Australia's international internet traffic travels through around 15 submarine cables laid across the ocean floor.

The embassy described the cables as the arteries of modern life, stressing that they can be damaged by relatively ordinary maritime activity, including a ship's anchor dragging across the seabed at night.

Photo: Shutterstock

The warning also highlights the broader security risks facing critical underwater infrastructure, which has become increasingly important to communications, international trade and national security.

The issue has gained urgency following a series of submarine cable disruptions in international waters, including incidents in the Baltic Sea and around Taiwan, as well as the latest wave of bomb threats against passenger planes, airports and media companies in Europe.

Australian Defence Minister Richard Marles has previously described the frequency and scale of damage to undersea infrastructure as historically unprecedented.

The vulnerability is particularly significant for Australia because much of its international digital connectivity depends on a relatively small number of physical connections.

Damage to several cables could affect banking, healthcare, government communications and businesses that rely on overseas data services.

The AUKUS Partnership

Australia, the United States and the United Kingdom are addressing the threat through their AUKUS security partnership. The three countries have announced plans to develop and deploy unmanned underwater vehicle technology to improve their ability to monitor and protect critical infrastructure beneath the sea.

The initiative is intended to strengthen surveillance and response capabilities in the maritime domain, including against potential threats to undersea cables and pipelines.

The challenge extends beyond Australia. Submarine cables are essential to global internet connectivity, carrying the vast majority of international data traffic between continents.

Their protection has become an increasingly important issue for governments concerned about the security of critical infrastructure and the possibility of deliberate interference.