Submarine Cables: EU Warns of Dependence on US Hyperscalers

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Incidents in the Baltic Sea have shaken those responsible awake. How vulnerable is Europe's connection to the rest of the world via subsea cables? An EU expert group on submarine cable infrastructure investigated this question. The report, presented in October 2025, highlights not only various risks of cable disruption and difficulties with repairs, but also something else: how heavily Europe is actually dependent on US tech companies.

US hyperscalers already control 90 percent of the capacity on the transatlantic route and are continuously expanding their dominance on other routes as well. “The share of traditional telecommunications companies in the EU has rapidly declined over the past ten years while US hyperscalers are constantly expanding their presence,” the 38-page document, created on the initiative of the EU Commission, states. The four largest players—Google, Meta, Microsoft, and Amazon—already accounted for 71 percent of the international capacity used in 2024, compared to just 10 percent in 2014.

Big Tech from the USA needs enormous bandwidth

The shift in power dynamics has a simple reason: hyperscalers require enormous bandwidth to connect their cloud regions on different continents. European telecommunications providers cannot keep up with these investments, partly because Europe does not have its own “hyperscaler” and the traffic volume of traditional operators does not justify such expenses.

“The lack of European investment in intercontinental submarine cables means that EU Member States are significantly reliant on cables laid by non-EU actors for their capacity needs on some routes,” the report warns.

Components partly only available outside the EU

Even more serious are the dependencies in the supply chain. While Europe has Alcatel Submarine Networks (ASN) from France, one of the three leading global providers of submarine cables, capacities for critical components are lacking. Optical fibers for long-haul submarine cables are manufactured exclusively by US companies (Corning, OFS) and Japanese companies (Sumitomo Electric). Optical pumps for repeaters come only from US manufacturers. And in microchips for transponders, Taiwanese and South Korean providers, namely TSMC and Samsung, dominate.

When assessing threat actors, the report also becomes specific. Russia has intensified its underwater military exercises at depths of over 6000 meters; NATO commanders reported suspicious Russian activities around submarine cables in the Baltic Sea in 2023, it states. China is also explicitly named. In March 2025, the China Ship Scientific Research Centre revealed the development of a remotely controlled underwater vehicle capable of severing armored submarine cables at depths of up to 4000 meters.

The expert group outlines seven risk scenarios. These range from coordinated sabotage of cables and attacks on cable landing stations to targeted power outages and natural causes, such as damage from natural events.

Repair fleet is aging

Another problem: capacities for repairing damaged cables are coming under pressure. Although almost all disruptions in Europe were resolved within 24 hours between 2022 and 2024 – only two to three percent were delayed due to a lack of maintenance vessels. However, the fleet is aging, and some repair vessels are being converted into cable-laying vessels to serve the growing demand from hyperscalers.

As a consequence, the expert group proposes EU-wide stress tests for submarine cable infrastructure for the first time – similar to those already conducted in the energy sector. The tests are intended to examine resilience against extreme but realistic scenarios in three escalation levels.

Satellites are hardly any help

The report significantly dampens hopes for satellite constellations in low Earth orbit as an alternative: “The most advanced satellite constellations provide only a fraction of the bandwidth of a single cable.” However, satellites could serve as a backup for critical, low-bandwidth applications such as emergency communication.

97 to 98 percent of global internet traffic runs via submarine cables. Although the EU has over 300 cable landing stations, the dependence on a few critical nodes remains high. 90 percent of traffic between Europe and Asia passes through the Red Sea – a bottleneck that has already been affected multiple times by Houthi attacks in 2023/24. Dependence on the United Kingdom also remains: data traffic between Ireland and the continental EU largely runs via the United Kingdom.

(mki)