Taiwan's Submarine Cable Network

What it is

Taiwan depends on a network of 14 international and 10 domestic submarine cables for virtually all external internet connectivity. The cables carry over 95 percent of Taiwan's international data traffic, with no meaningful terrestrial alternative. Three landing stations handle international traffic: Toucheng in Yilan County on the northeast coast, Tamsui in New Taipei City, and Fangshan in Pingtung County in the south. Chunghwa Telecom, the state-linked incumbent carrier, holds ownership stakes in most cables and operates all three landing stations. The collective designed capacity of the international cables exceeds 300 terabits per second.

Key cables include the Asia-Pacific Gateway (APG), New Cross Pacific (NCP), APRICOT (12,000 km, consortium including Meta, Google, and Chunghwa Telecom, launched 2025), and Southeast Asia-Japan Cable 2 (SJC2, 10,500 km, launched 2025). Google's Taiwan-Philippines-US (TPU) cable (13,600 km) is scheduled to enter service in 2026, and Meta's ORCA system (12,482 km, landing at Toucheng) is due in 2027.

History

Taiwan built out international cable connections through the 1990s and early 2000s as its semiconductor and electronics industries integrated with global supply chains, treating the network as commercial infrastructure. That framing changed in February 2023, when two Chinese-registered vessels severed the two cables linking Matsu, an offshore island chain of about 13,000 residents, to the main island. The first cable was cut on February 2; the second was damaged February 8. Matsu residents were without broadband for over 50 days while a repair vessel cleared its schedule. Repair costs ran between US$1 million and US$3 million. The incident forced a public reckoning with the network's fragility, particularly Taiwan's complete lack of domestic cable repair vessels.

Current state

Taiwan now records roughly 7 to 8 cable damage incidents per year. Between 2019 and 2023, Taiwanese authorities documented 36 external-force or compression damage cases, with 2023 reaching 12 incidents. Two further incidents followed in early 2025: the vessel Shunxin 39 damaged the TPE cable north of Taipei in January, and the Hong Tai 58 damaged the TPKM-3 cable connecting Penghu to the main island in February. Taiwan's Coast Guard has blacklisted 96 suspicious vessels, mostly Chinese-owned and sailing under flags of convenience from Mongolia, Cameroon, and Sierra Leone. In June 2026, a Taiwanese court convicted the Chinese captain of the Hong Tai 58 of deliberate cable damage and sentenced him to three years in prison, the first conviction of its kind in Taiwan.

Taiwan has no cable repair vessels of its own; global fleets are heavily booked, making delays of six to eight weeks typical. Taiwan's Executive Yuan approved draft amendments to the Telecommunications Management Act in 2025 to criminalize cable interference more explicitly and to streamline vessel inspection timelines, which currently run up to 29 months. Chunghwa Telecom committed in March 2026 to a total investment of over NT$2.9 billion in the AUG East cable project, linking Taiwan to Japan and South Korea in a consortium with US and Japanese partners.

Relationships

Cable integrity is a first-order variable in any Taiwan Strait contingency. PLA naval exercises push Chinese vessels into cable corridors, and Taiwan's defense planners treat pre-conflict cable severance as a probable early move in any blockade scenario. The 台湾至马祖海底电缆再次断裂，微波备用线路维持东引在线 incidents, repeated targeting of the same domestic routes by Chinese-crewed vessels with disputed intent, have made Matsu a live test bed for gray-zone cable coercion. War games including 台湾举行首次公开命名为「应对海上胁迫」的图上演练 now model internet-disruption scenarios alongside naval blockade contingencies, and the pattern informs US legislative proposals such as the Critical Undersea Infrastructure Resilience Initiative Act (S.2222, introduced 2025).

Taiwan is pursuing redundancy across multiple approaches: five new cables with armored protective sheathing (two international, three domestic), low-Earth-orbit satellite partnerships for government and military backup, and microwave relay links of the type that kept Dongyin connected during the April 2026 outage.

What to watch

• Whether Taiwan secures dedicated cable repair vessel capacity or priority contracts by end-2026.
• Completion of the Taiwan-Matsu No. 4 domestic cable (originally targeted June 2026) and activation of the TPU international cable.
• Further prosecutions under Taiwan's amended cable-protection legislation and any vessel detentions by Taiwan's coast guard.
• Any simultaneous multi-cable incident that exhausts available repair capacity, a scenario now built into Taiwan Strait defense planning.