Taiwan and connecting fiber optic cables

Taiwan relies on a network of undersea fiber-optic cables for international and domestic connectivity, making it highly dependent on these critical infrastructures while also vulnerable to geopolitical disruptions.Overview of Taiwan's Fiber-Optic InfrastructureTaiwan's global internet and telecommunications connectivity is primarily supported by 24 undersea cables, including 14 international and 10 domestic lines, which link the island to major global networks and neighboring regions . These cables carry vast amounts of data, including internet traffic, banking transactions, and emergency communications, forming the backbone of Taiwan's digital infrastructure . Modern cables use fiber-optic technology, transmitting data as pulses of light through glass fibers, allowing high-speed, high-capacity communication across thousands of kilometers .Key International ConnectionsOne of the major trans-Pacific systems is the Taiwan-Philippines-US (TPU) cable, which spans approximately 13,470 kilometers and connects Taiwan with the United States and the Philippines . The TPU system features 16 fiber pairs on its trans-Pacific trunk and 20 fiber pairs on branches to Taiwan and the Philippines, with a total design capacity of up to 260 Tbps . The TPU cable incorporates advanced technologies, including multi-core fiber on its branches to Taiwan, enhancing data throughput and reliability . The Dawu landing station in Taiwan is owned by Chunghwa Telecom, ensuring local control over the cable's operations .Vulnerabilities and Geopolitical RisksTaiwan's undersea cables are strategically vulnerable due to their location in the Taiwan Strait, one of the world's busiest shipping lanes . In recent years, there have been multiple incidents of suspected sabotage by Chinese-crewed vessels, including the severing of cables connecting the Matsu Islands, Penghu Islands, and northern Taipei between 2023 and 2025 . These incidents are part of broader “gray zone” tactics, where hostile actions are conducted without triggering full-scale conflict, potentially disrupting Taiwan's economy, military coordination, and emergency response systems . Taiwan has responded by diverting communications to alternative cables and increasing monitoring of vessels near critical cable locations .Strategic ImplicationsThe vulnerability of Taiwan's undersea cables highlights the importance of domestic repair capabilities, alternative connectivity solutions such as satellite internet, and international cooperation to safeguard communications . Additionally, China's broader undersea strategy, including seabed mapping and cable installation under the Digital Silk Road initiative, underscores the geopolitical significance of submarine cables in the region . Ensuring the security and resilience of these networks is critical for Taiwan's national security and economic stability. In summary, Taiwan's fiber-optic cable network is a vital component of its digital infrastructure, connecting the island to global networks while also exposing it to strategic vulnerabilities that require ongoing monitoring, technological investment, and international collaboration .