The Achilles’ heel of the digital age lies beneath our oceans: fragile undersea cables that, when severed, can plunge entire regions into digital darkness. Undersea cables are the lifelines of modern economies: they carry over 95 percent of the world’s internet traffic, making them one of the most critical—yet vulnerable—pieces of infrastructure in the 21st century. When these cables go dark, everything from banking transactions to emergency response systems can grind to a halt. These fiber-optic lines stretch across the seafloor, making them ideal targets for sabotage with minimal resources, while creating just enough plausible deniability for malicious actors to dodge any consequences.
To date, Taiwan’s limited response to China’s cable cutting (see discussion below) has not conveyed a desire to deter further action. Taipei should increase its response capabilities to monitor and intercept ships loitering near cables, develop domestic cable repair capabilities, and invest in alternative connection platforms such as satellite-based internet.
Chinese Sabotage Directed at Taiwan’s Undersea Communications Cables
In early 2023, Chinese-registered vessels severed two undersea cables, knocking Taiwan’s Matsu Islands offline. China’s preferred explanation is that these incidents are just unfortunate maritime accidents. Beijing claimed that the 2023 incidents were a coincidence, and even blamed Taiwan for manipulating the facts. Given that the Taiwan Strait is one of the world’s busiest waterways, with more than 1,000 cargo ships passing through weekly, accidental damage by anchors or fishing nets is not impossible. However, more recent disruptions, and Chinese-flagged vessels lingering near key cable locations, suggest a more disturbing pattern.
For Taiwan, an island dependent on just 24 cables (14 international and 10 domestic) for global connectivity, this is far more than a nuisance: it is a significant national security risk, and Beijing knows it. Through such disruptive measures, China can paralyze Taiwan’s ability to communicate with the outside world—undermining its economy, military coordination, and capacity for emergency response, all before firing a single shot.
China has been involved in multiple malicious actions directed at Taiwan’s cables:
- February 2023: China severed two cables supplying the Matsu Islands, cutting residents off from internet services for weeks.
- January 2025: Another Chinese vessel, the Shunxin 39, allegedly damaged the TPE cable north of Taipei.
- February 2025: The Chinese-crewed Hong Tai 58 damaged the TPKM-3 undersea cable connecting the Penghu Islands with Taiwan.
Image: A graphic depicting incidents of suspected undersea cable sabotage around Taiwan from early 2023 to early 2025. (Image source: Taiwan Security Monitor / George Mason University)
Larger Suspicious Evidence of Chinese Cable Sabotage
Beijing would have you believe that these ships are uniquely unlucky, hitting Taiwanese cables (and in the Western Pacific, only Taiwanese cables) by accident. In addition, Taiwan’s Coast Guard intercepted Chinese research vessels allegedly gathering seabed data that could help locate these cables with precision. Furthermore, these sabotage incidents match incidents in the Baltic: in November 2024, a Chinese vessel, Yi Peng 3, reportedly cut cables between Finland, Germany, Lithuania, and Sweden using similar tactics (and as part of a wider pattern of Baltic sabotage suggestive of collusion with Russia).
Suspicions are also raised by China’s active development of cable-cutting tools. Researchers at China’s Lishui University have designed an anchor-like device explicitly intended to sever submarine cables. Maritime security experts have reviewed the cable-cutting device’s specifications. It is optimized for operations at depths beyond typical fishing activity, and designed with features that clearly indicate a sabotage purpose. While the technology may have dual-use applications (e.g., cable repair), legitimate repair ships follow international protocols, including advance notification and transparent operations. By contrast, the vessels involved in these incidents have no history of cable maintenance, and operate with secrecy and unpredictability.
The economic impact of undersea cable disruptions is substantial. According to Taiwan’s Ministry of Economic Affairs, the 2023 incidents alone cost millions of US dollars to repair. Further, each major cable outage disrupted internet traffic, delayed financial transactions, and required emergency rerouting.
Compounding the issue is Taiwan’s dependence on foreign cable repair ships, primarily based in Japan, Singapore, and the Philippines. Repair delays can stretch from six to eight weeks, or longer, especially in bad weather or during regional demand spikes. Taiwan is vulnerable, and every prolonged delay aligns with a message from Beijing: that Taiwan’s digital lifeline can be disrupted, and that its recovery is uncertain.
Beijing’s Unconvincing Denials
Beijing and its media mouthpieces have pivoted from denial to disinformation, suggesting that Taiwan is orchestrating these disruptions to stoke international sympathy or escalate tensions. In a written statement to Reuters, China’s Taiwan Affairs Office (國務院臺灣事務辦公室) claimed that more than 100 cable incidents occur globally each year, dismissing them as “common maritime accidents.” It accused Taiwan of fabricating the threat and hyping the “so-called gray zone.”
The Taiwanese Coast Guard isn’t convinced. It has blacklisted 96 suspicious vessels, mostly Chinese-owned and flying flags of convenience from countries like Mongolia, Cameroon, and Sierra Leone, for close monitoring.
Taiwan depends on these cables for critical functions, from military communications to financial systems. The 2023 Matsu incident didn’t give Taiwan political leverage; it disrupted banking, commerce, and emergency services. It is not logical for Taiwan to cripple itself to fabricate a crisis. More importantly, the pattern of incidents consistently overlaps with the presence of Chinese vessels.
This fits neatly into China’s long-running gray-zone warfare strategy, using non-military means to apply pressure while avoiding open conflict. From ship harassment to daily incursions by Chinese jets, the goal remains the same: erode Taiwan’s stability. Cutting cables is just the latest addition to this growing toolkit.
Recognizing the seriousness of these threats, Taiwan’s Defense Minister announced in March 2025 that cooperation between the Navy and Coast Guard is underway. This marks a strategic shift from viewing cable protection as a bureaucratic afterthought to treating it as a national defense priority.
The next time another cable goes dark, we should skip the diplomatic hedging and call it what it is: an attack on Taiwan’s infrastructure under the guise of plausible deniability.
Image: The Shunxin-39 (AKA Xing Shun 39), a Hong Kong-registered vessel suspected of damaging undersea telecommunications cables off the northern coast of Taiwan in January 2025. (Image source: Lloyd’s List / ROC Coast Guard)
The Way Forward: Building Digital Resilience
Taiwan doesn’t just need more ships; it needs better information. Requiring more vessels to use automatic identification systems would improve maritime domain awareness, and give the Coast Guard cause to stop suspicious ships (i.e., those not transmitting) before they approach cables. Investments in radar, satellite imaging, and electronic intelligence should also be prioritized. Doing this would decrease response times and allow Taiwanese vessels to intervene before sabotage takes place. Current defense priorities such as large purchases of conventional power like F-16s do not solve this, and are less useful in countering gray zone operations. Amendments for this kind of legislation are already being proposed.
Additionally, Taiwan needs more cables. But with system inspections taking roughly 29 months to complete, Taiwan must streamline this process by expanding international partnerships. Chunghwa Telecom is already taking steps, recently joining the E2A undersea cable project with partners in the United States, Japan, and South Korea aiming to improve connectivity across the Pacific. These partnerships are key to allocating resources, internationalizing infrastructure, and bringing more global attention to Taiwan’s vulnerability.
Taiwan also urgently needs its own dedicated cable repair ship. Delays can cost tens of millions in economic losses. Domestic repair vessels could reduce downtime from months to days. While refitting existing ships, or developing new ones, are major investments, the strategic payoff is clear. Taiwan should explore creating a maritime infrastructure security fund, pooling resources from government and telecom firms alike.
Finally, Taiwan must diversify beyond seabed infrastructure. Satellite-based internet won’t replace the capacity of undersea bandwidth, but it can preserve essential services, such as government communications, financial transactions, and emergency coordination, during outages. Recent expansion into low-Earth orbit (LEO) satellite constellations provides a viable backup network that is harder for China to disrupt. Unlike undersea cables, LEO systems are less vulnerable to physical sabotage and can be deployed quickly in response to crises. Taiwan is also exploring partnerships with Amazon’s Project Kuiper and other LEO providers.
The undersea cable conflict may seem obscure next to warplanes and missile drills, but it’s no less dangerous. What happens to Taiwan today could happen to other democracies tomorrow. It’s time to treat this for what it is—a frontline in the shadow war over digital infrastructure—and act accordingly.
The main point: Taiwan is facing an intentional and sustained campaign of undersea cable sabotage by China—part of Beijing’s broader campaign to undermine Taiwan’s sovereignty through shaping the narrative on how the world sees these issues. To combat this, Taiwan should invest more in cable installation and repair, as well as digital resilience measures to maintain telecommunications connectivity.
