Published 14:29 IST, January 30th 2025
China’s ‘Grey-Zone’ Tactics? Taiwan’s Maritime Security Alarm Bells Ring After Multiple Cable Disruptions
Taiwan relies heavily on 14 international and 10 domestic undersea cables for global connectivity, and disruptions to these could have serious implications.

Taipei, Taiwan – Taiwan’s Coast Guard has identified 52 Chinese-owned vessels flying flags of convenience, categorizing them as "suspicious" due to their movements near the island’s critical undersea communication infrastructure. Out of these, 15 have been classified as potential threats, with five ships reportedly loitering in Taiwan’s territorial waters for over 15 days. Authorities fear that these vessels could be part of a broader strategy by China to undermine Taiwan’s communication networks, a key component of its national security.
Undersea Cables: A Vulnerable Target
Taiwan, a key hub for global internet and communication infrastructure, relies on 14 international and 10 domestic undersea cables. Disruptions to these cables could severely impact Taiwan’s ability to maintain stable communication with the world, a risk the government takes seriously amid heightened tensions with China.

Since 2023, Taiwan has accused China of attempting to sabotage its undersea cables on at least three occasions:
- January 2025: A Chinese-linked cargo ship, Shunxing-39, was suspected of damaging an undersea cable near Taiwan’s northeastern coast. The Taiwanese Coast Guard detained the vessel for investigation following reports from Chunghwa Telecom.
- November 2023: The Chinese vessel Yi Peng 3 was suspected of severing two undersea data cables in the Baltic Sea. The cables were cut in Swedish territorial waters, raising concerns that similar tactics could be used against Taiwan.
- February 2023: Two undersea cables connecting Taiwan to the Matsu Islands were severed within a week, cutting internet access for 14,000 residents. Taiwanese authorities linked the damage to a Chinese fishing vessel and a freighter, but no direct evidence of sabotage was found.
Between 2017 and 2023, Taiwan’s undersea cables experienced around 30 breaks, further intensifying concerns over security vulnerabilities. Taiwan’s government fears that these incidents may be part of China’s broader "grey zone" tactics—covert or ambiguous actions designed to pressure Taiwan without triggering a direct military confrontation.
China’s Strategic Interests in Disrupting Undersea Cables
Security analysts suggest that China’s interest in targeting Taiwan’s undersea cables is driven by several strategic objectives:
- Disrupting Communication Networks – Cutting these cables could significantly impact Taiwan’s ability to coordinate defence operations during crises or conflicts.
- Undermining Public Confidence – By creating vulnerabilities in Taiwan’s critical infrastructure, China could shake public trust in the government’s ability to protect national security.
- Hybrid Warfare Strategy – Undersea cable sabotage fits into a larger strategy that includes cyberattacks, espionage, and other covert operations aimed at destabilizing Taiwan.
- Leverage in Negotiations – By threatening Taiwan’s communications, China could gain an advantage in diplomatic or military negotiations concerning the island’s future.

Adding to concerns, Chinese companies involved in undersea cable repairs have come under international scrutiny. The state-controlled S.B. Submarine Systems (SBSS) has been flagged as a potential security risk. U.S. officials have warned telecom providers about SBSS, citing suspicions that the company may be hiding its vessels’ locations, raising fears of possible espionage or sabotage.
Taiwan’s Countermeasures
In response to these threats, Taiwan is implementing a multi-pronged strategy to safeguard its undersea communication infrastructure. The government is considering developing its own cable repair systems to reduce reliance on international services, which can delay restoration efforts during crises. This initiative may involve partnerships with local shipbuilders and foreign experts from the U.S. and Japan.
Meanwhile, Taiwan’s Coast Guard is intensifying its tracking of suspicious vessels, including aerial surveillance with drones to monitor undersea cable zones in real time. Authorities are pushing for significant investment in new undersea cables and data centres. The government is also exploring financing models similar to those used by the European Commission to secure submarine cable infrastructure.

Taiwan is also working with allies, including the U.S. and Japan, to bolster its maritime security and safeguard its data networks from potential Chinese interference.
Taiwan’s concerns over Chinese maritime activities have sparked international debate, with the U.S., Japan, and European nations expressing growing apprehension over China’s increasing influence in global undersea cable networks. Experts warn that if China continues targeting Taiwan’s communication infrastructure, it could set a dangerous precedent for similar actions in other regions, including the South China Sea and beyond.
Updated 14:29 IST, January 30th 2025