Sabotage of critical infrastructure on the seabed has become a growing concern, with Taiwanese authorities this month charging the captain of a Chinese cargo ship with damaging a vital underwater communications cable connecting Taiwan to the Penghu Islands off the Chinese coast. While difficult to prove, such actions are considered a dangerous part of “grey zone” tactics aimed at targeting weak spots in an enemy’s defenses.
Increasing Sabotage Cases and Suspicious Ships
The Taiwan Coast Guard detained the Hong Tai 58, a Togolese-flagged cargo ship with a Chinese crew, in late February on the charge. A similar incident occurred north of Taiwan in January, but in that case, the culprit was determined to be a Hong Kong-owned commercial vessel. Taiwan has already reported five cases of seabed cable damage this year, with three each in 2023 and 2024. The Taiwan Coast Guard has blacklisted about 100 suspicious vessels with Chinese connections, highlighting the seriousness of the problem.
Concerns and Accusations in the International Arena
Although Beijing has denied such allegations, many observers believe such malicious actions are part of China’s increasingly coercive behavior toward Taiwan. U.S. Senator Jacky Rosen (D-Nev.) slammed China’s “reckless, coercive and aggressive actions” in a statement to the House Armed Services Committee, describing the sabotage of undersea cables as a “particularly worrying tactic.” At the same hearing, Admiral Samuel Paparo, Commander of the U.S. Naval Indo-Pacific Command (INDOPACOM), also acknowledged the existence of sabotage attempts, particularly against undersea internet cables around Taiwan. Shortly after Taiwan seized Hong Tai 58, media reports revealed that the state-run China Naval Scientific Research Center had patented a deep-sea device that could “cut the world’s most powerful underwater communications or power lines.” This development further fuels Taiwan’s concerns.
The Critical Goal in a Large-Scale Conflict: Disruption of Communications
It is clear that one of China’s priorities in a large-scale military operation against Taiwan (such as a naval blockade or a full-scale invasion) would be to isolate the island and disrupt civilian and military communications. Sabotage of undersea communications cables is considered an important part of this strategy.
US Emphasizes Countermeasures and Redundancy
In testimony to US lawmakers, Admiral Paparo proposed two key countermeasures to China’s sabotage of the cables. First, penetrating the targeting chain through intelligence-gathering activities and then establishing a deterrent presence with military forces “in places where they would otherwise cut those cables.” Second, building resilience. This includes expanding redundant communications networks and a large constellation of satellites in low Earth orbit (LEO) to ensure the flow of information continues uninterrupted.
Technology Companies Hopeful for New Market
Meanwhile, marine technology companies sense a new market is emerging in the area of protecting and repairing underwater infrastructure. Saab Australia’s general manager Andy Keough says his company is well-positioned to support governments in defending underwater infrastructure with its mine-clearing technologies. Keough points to the potential of autonomous underwater vehicles (AUVs) and seabed sensors to monitor infrastructure and provide real-time maritime domain awareness. He also stresses that developing the ability to quickly repair infrastructure or reroute communications via alternative routes is also critical. Saab’s Sabertooth AUV can act as a permanent underwater “resident” for inspection and repair missions, with the help of a subsea docking station.
French company Exail has signed a contract with the French army to design an AUV capable of diving to depths of 6.000 metres and reprogramming itself during a mission to counter seabed warfare. Thales Australia is also aiming to capture a share of this new market with its detection equipment. Gavin Henry, from the company’s underwater warfare unit, says Thales’ Blue Sentry technology could be used to detect potential threats with its slim-line towed array.
Increasing Regional Cooperation and Maritime Area Awareness
Ross Babbage, CEO of the Australian Strategic Forum, says undersea infrastructure is under serious threat and a nationwide, layered approach is needed to combat these threats. Babbage says the use of technology such as automatic identification systems (AIS) on ships can play a key role in detecting suspicious deviations. A spokesperson for the Australian Department of Defence said the military has a range of capabilities to monitor and respond to threats to undersea communications cables and works with other agencies specialising in cybersecurity to protect infrastructure. However, much of this information is classified.
Taiwan’s latest accusation against China further underscores how critical the security of submarine communications cables is to regional security and heightens the need for international cooperation and enhanced maritime domain awareness to counter such gray zone tactics.
