Submarine cables are becoming a critical vulnerability in AI infrastructure as computing and data are increasingly distributed among geographically distant centers. The network passes through areas exposed to outages and geopolitical tensions, while limited repair capacity could prolong disruptions and raise the operating costs of distributed systems.
The submarine cable network stretches for more than 1.7 million kilometers and carries more than 99% of international data traffic. These cables connect data centers and cloud networks across continents, making their capacity and latency influential factors in distributed AI workloads.
Distributed computing expansion drives demand
Cable outages or rerouting data over longer paths can reduce available capacity, slow connections and raise the operating costs of some services and training operations. Companies are increasingly interested in geographically distributed training because of the difficulty of providing the power, space and computing capacity needed for large models at a single site.
These architectures rely on exchanging model updates among multiple nodes, so higher latency or packet loss can reduce the efficiency of computing resources and extend training times. Estimates by research firm TeleGeography indicate that growth in AI workloads, particularly training data and connections between data centers, could increase demand for long-haul networks.
TeleGeography’s 2026 Global Bandwidth Research Service map tracks about 694 cable systems, while the value of new systems scheduled to enter service between 2026 and 2029 exceeds $16 billion. This reliance has prompted major technology companies to finance cable systems and secure dedicated international capacity to improve links between computing, storage and inference sites and make their networks more resilient.
Red Sea and route concentration risks
The expansion of cable networks comes amid concerns that routes are concentrated in busy or contested straits and sea corridors. The Red Sea and Bab al-Mandab stand out as a major passage for cables linking Europe, Asia, the Middle East and East Africa.
In March 2024, several cables were damaged simultaneously near the Yemeni coast, affecting about 25% of regional data traffic between Asia, Europe and the Middle East. In September 2025, cable outages in the Red Sea led to data traffic being rerouted over longer paths, increasing latency between Europe and Asia.
The disruption affected connectivity to India, Pakistan and several Gulf countries, while Microsoft told Azure customers that latency could increase for traffic transiting between Asia and Europe via the Middle East. The platform hosts commercial AI services, including Azure OpenAI.
Tensions in the Pacific and Baltic Sea
In the Pacific, cables have become part of the technological and geopolitical rivalry between the United States and China. Washington halted operation in 2020 of a section of a cable that was planned to reach Hong Kong, citing concerns related to Chinese espionage.
Taiwan hosts as many as 15 international submarine cables, making it vulnerable to widespread disruption if several routes are damaged simultaneously. In February 2023, the two cables linking the Matsu Islands to Taiwan were damaged in two incidents involving Chinese vessels, leaving about 14,000 people without internet access for more than 50 days.
Taiwanese authorities also suspected in January 2025 that the ship Shunxin 39 had damaged a cable linking Taiwan with Asia and the United States. The following month, Taiwan’s coast guard detained the ship Hong Tai 58 on suspicion of cutting a submarine cable, before a new cut was recorded near Matsu in April 2026.
In the Baltic Sea, at least 11 cables have been damaged since October 2023. Authorities suspected the Chinese ship Yi Peng 3 in November 2024 of cutting two cables linking Finland with Germany and Sweden. Finland then detained the oil tanker Eagle S in December on suspicion of cutting communications cables between Estonia and Finland.
NATO launched the Baltic Sentry mission on January 14, 2025, with the participation of frigates, maritime aircraft and unmanned vessels. The alliance uses artificial intelligence and autonomous systems to monitor maritime infrastructure, but damage incidents continued in the region toward the end of 2025.
Limited and aging repair fleet
Limited repair capacity has compounded the impact of cable disruptions. The global fleet specializing in laying and maintaining cables numbers no more than 80 vessels, including about 22 repair ships. Estimates indicate that 47% of cable-laying vessels and 64% of repair vessels will approach the end of their estimated 40-year service lives by 2040.
A report prepared by TeleGeography and InfraAnalytics for the SubOptic Association estimates that addressing the gap will require an investment of about $3 billion through 2040. This includes building 15 replacement vessels and 5 additional vessels to meet demand, particularly in the southwest and northwest Pacific.
The average time needed to repair cable faults was about 40 days in 2023, according to data from the International Cable Protection Committee cited by Recorded Future. In February of the same year, all five cables linking Vietnam to the world were damaged, resulting in a loss of 75% of data transmission capacity. Repairs were not fully completed until late November.
Repair operations depend not only on the availability of specialized vessels and crews; a repair ship also needs authorization from the country hosting the cable. In contested waters, overlapping jurisdictions may delay access to the site of a fault, prolonging reduced capacity or higher latency and increasing pressure on services and systems distributed across different geographic regions.
