Submarine cable infrastructure forms the backbone of global digital communications, carrying approximately 97–98% of international internet traffic. Against the backdrop of accelerating digital transformation, growing data volumes, and intensifying geopolitical competition, the security and resilience of these infrastructures have become essential components of the European Union’s economic and technological security.
The rapid development of the market is driven by investments from major global technology companies, leading to an increase in European countries’ dependence on infrastructure and technologies controlled by actors outside the Union. In this context, the European Union aims to strengthen the legislative and institutional framework designed to protect submarine cable infrastructure through measures aimed at increasing resilience, reducing vulnerabilities, and strengthening strategic autonomy.
An October 2025 report by the EU Submarine Cable Infrastructure Expert Group on submarine security and resilience analyses the regulatory framework applicable to submarine cable infrastructure at the international and European levels, highlighting its strategic importance, market developments, key dependencies and vulnerabilities, as well as the challenges associated with maintaining, repairing and protecting this critical infrastructure.
The legislative and policy framework for the security and resilience of submarine cable infrastructure
The international, European and national regulatory framework
Relevant legislation and policies (at the international, EU, and national levels) cover a wide range of areas, some of which focus specifically on submarine cable infrastructure (for example, Recommendation (EU) 2024/779 and the Cable Action Plan), while others address cables as part of a broader range of issues. Maritime security, physical security and cybersecurity are the main policy areas directly relevant to the security and resilience of submarine cable infrastructure.
However, several other aspects must also be taken into account, such as maritime governance (established in particular under the United Nations Convention on the Law of the Sea (UNCLOS)), competitiveness, economic security, technological sovereignty, internal security, defence, and foreign policy, including cooperation with the North Atlantic Treaty Organization (NATO) and other multilateral organizations.
European Union policies on submarine cable infrastructure
The annex to this report provides an overview of the policy, legal and administrative issues relevant to submarine cable infrastructure, at both the EU and national levels.
The document is based on feedback received from EU Member States, collected through a survey conducted by the Expert Group in 2024, as well as on the aforementioned study commissioned by the European Commission.
Key findings
The annex also examines the market for submarine data cables, the value chain and the ecosystem, and identifies several key findings relevant to the development of EU policies on the security and resilience of these infrastructures (and, potentially, other submarine infrastructures): 97–98% of global internet traffic transits through submarine cables.
Despite its significant terrestrial network infrastructure, the EU relies no less on submarine cables than other regions of the world.
Therefore, it is essential for the EU’s economic security to have resilient submarine cable infrastructure and to reduce its dependence on entities outside the EU, just as it is for the EU’s competitors.
Global market developments and the European Union’s strategic dependencies
The declining role of European telecommunications operators
The share of submarine cable capacity owned by traditional telecommunications operators in the EU has declined rapidly over the past 10 years, while U.S. hyperscalers are steadily expanding their footprint. Hyperscalers already account for 90% of the total capacity of the cable route connecting the U.S. and Europe, and they are increasing their share on the Europe-Africa and Europe-Asia routes. The lack of European investment in transcontinental submarine cables means that EU member states rely heavily on submarine cables installed by non-EU players to meet their capacity needs on certain routes.
Decline in European investment in undersea infrastructure
Investments by traditional telecommunications operators in regional cable systems have declined, constrained by financial pressures and modest commercial prospects, largely due to low traffic on these secondary routes and growing competition from other players.
There is also pressure on cable repair capacity due to an aging maintenance fleet and a substantial increase in the total length of cable installed by hyperscalers, which absorbs a significant portion of repair resources. Furthermore, some repair vessels have been repurposed as installation vessels to meet the growing demand for submarine cable deployments, while some hyperscalers may consider developing their own cable repair capabilities.
Challenges related to the maintenance and repair capabilities of submarine cables. European industrial capacities and supply chain vulnerabilities
Finally, the EU has strong capabilities in cable installation and maintenance. Alcatel Submarine Networks (ASN), headquartered in France, is one of the three leading global suppliers of submarine cables.
However, the EU also has a critical dependence on non-EU entities in the cable supply chain (for example, optical fibre for long-distance submarine cables is manufactured exclusively by American and Japanese companies; optical pumps in repeaters are manufactured only by U.S. companies; and the production and supply of microchips for transponders are largely controlled by Taiwanese and Korean suppliers.
The evolution of submarine cable capacity and the impact of hyperscalers on global connectivity
The expansion of submarine cable capacity over the past 10 years has been driven primarily by the growing demand for international bandwidth from the four largest hyperscalers (Google, Meta, Microsoft and Amazon). The need for these hyperscalers to interconnect their cloud regions across different continents has shaped the industry. On the transatlantic route, capacity ownership is entirely dominated by hyperscalers due to their need to interconnect cloud regions in the U.S. and Europe.
European investment in transatlantic submarine cable projects remains limited compared to the U.S., due to the fact that Europe does not have “its own hyperscaler” and that traditional telecom operators and carriers do not have sufficient traffic volume to justify such investments.
The European Union’s dependence on infrastructure controlled by external actors
In the Red Sea and Indian Ocean region, hyperscalers’ own capacity is currently limited due to underdeveloped cloud infrastructure in the Middle East and Asia. However, with three high-capacity cables currently being deployed, they will soon have access to significant capacity through their respective consortia.
This means that, if the current trend continues, EU Member States will become increasingly dependent on external actors for their own connectivity needs with North America and, eventually, with Asia and Africa, raising concerns about the EU’s technological sovereignty and economic security.
The total capacity of submarine cables connecting EU member states to one another and to third countries has increased from 318 Tbit/s in 2010 to 3,755 Tbit/s in 2024.
Submarine cables typically have a design life of 25 years, but this can be extended if it proves to be economically viable. However, for most cables, the end of their service life is dictated by the deployment of the next generation of submarine cables, which outperform the older cables and render them economically unviable.
The aging of submarine infrastructure and the need to ensure the continuity of public telecommunications services
The 33 newest cables provide 74% of the total capacity currently provided by submarine cables landing in at least one EU Member State. In contrast, the 89 oldest cables represent only 2% of the total current capacity of submarine cables landing in at least one EU country. However, traditional submarine cables carry public telecommunications traffic, unlike the new generation of cables owned by hyperscalers, which are laid for private use.
Therefore, when traditional cables reach the end of their useful life, telecommunications operators will need to ensure a certain level of capacity on these newer cables to meet the ever-increasing demand for data traffic and ensure the continuity of public service.
The global number of submarine cable faults has remained relatively constant over the past five years, as documented by the International Cable Protection Committee (ICPC). However, in Europe, the number of reported incidents has decreased significantly. This decline in submarine cable faults is attributed to improved education within the fishing community, higher cable-laying standards implemented by companies, and improvements in cable design. The decrease in the number of faults is also attributed to the decommissioning of the TAT-14 and SEA ME-WE 3 (SMW3) submarine cables, which were in shallow waters and had not been properly buried.
Submarine cables maintenance capacity and challenges regarding the efficiency of interventions in the European Union
On average, and across the entire European region, between 2022 and 2024, there was only one case per year in which a repair vessel could not be mobilized within 24 hours due to another repair, representing between 2% and 3% of the total number of reported incidents (therefore, 2021 can be considered an exception to this trend).
It is important to note that, over the past four years, providers of multifunctional vessel maintenance services in the Baltic Sea have consistently mobilized to repair cables within 24 hours, with no instances of delays due to an insufficient number of maintenance vessels.
The declining number of faults, combined with the ability to deploy a vessel within 24 hours (excluding delays in authorization), suggests that the current fleet of vessels is adequate for maintaining repair times under normal conditions.
Risks associated with a reduction in maintenance capacity
Although the fleet of maintenance vessels appears adequate under current conditions, a reduction in the number of maintenance vessels could significantly affect repair times. The reasons for a reduction in the number of vessels may include:
failure to replace decommissioned vessels or the acquisition by a new company of an existing maintenance company and the relocation of the fleet to another region of the world, or the acquisition of an existing maintenance company by another existing maintenance company and the exclusive use of the fleet for its own purposes, or damage to one or more vessels.
TeleGeography forecasts that the number of breakdowns in Europe is expected to rise to 52 in 2035, representing a 27% increase compared to 2024. Consequently, any reduction in the number of ships could mean that the maintenance fleet would not be sufficient to repair all breakdowns in a timely manner.
Therefore, maintaining existing maintenance capacity should be a central objective for the EU.
Authorization procedures and their impact on repair time
Based on the industry data collected for this report, the process of obtaining operating permits varies significantly across European regions. For example, in the Atlantic Ocean and the Mediterranean Sea, obtaining an operational permit for access to territorial waters could take anywhere from a few days to four weeks.
In contrast, the Baltic Sea benefits from operational permits that are valid for one to three years, eliminating the need to apply for individual permits for each repair and, as a result, reducing repair time. These differences exist within the EU, but the overall situation remains comparatively better than in other regions of the world, such as parts of Asia, where authorization processes can be significantly more complex and time-consuming.
Simplifying the authorization process in all Member States (for example, the authorization requirements set forth in legislation) would therefore be beneficial in terms of repair time. It would also be beneficial for the EU to negotiate with non-EU countries (for example, North African countries in the Mediterranean basin) to simplify the authorization process in regions where EU and non-EU countries are closely interconnected. These negotiations and any potential agreements should be based on the provisions of UNCLOS.
Main landing stations
Despite the EU’s extensive network of over 300 submarine cable landing stations and ongoing efforts to diversify landing locations, there remains a significant dependency on a few critical points. Specifically, the Red Sea remains a bottleneck, as 90% of the traffic between Europe and Asia transits through this corridor.
Some key landing stations (for example, Marseille (France) and Sines (Portugal)) have already been designed to be geographically redundant, which is crucial for major landing locations to minimize the impact of any cable damage.
Europe’s geographical location increases its vulnerability to threats. Several submarine cables connect remote island territories and cross the waters between member states, making them vulnerable to disruptions. In addition, island Member States (Cyprus, Ireland, and Malta) rely almost exclusively on submarine cables for internet connectivity, which means that the geographic diversity of landing stations and the resilience of individual landing stations are even more critical than for other Member States.
Data centres and cloud regions
The number of data centres and cloud regions in the EU is growing significantly, which is crucial for supporting the digital economy and ensuring data sovereignty. However, there are still several gaps and challenges that need to be addressed to enhance the resilience and efficiency of these infrastructures.
One of the main challenges affecting submarine cable infrastructure is Europe’s sovereignty over cloud solutions. Given the dominance of U.S. hyperscalers, the EU must strike a balance between promoting its domestic cloud industry and ensuring collaboration with non-EU actors to gain access to the essential technologies it needs.
In addition, efficient and resilient connectivity between data centres and submarine cable landing stations is crucial for uninterrupted data flows and for minimizing latency. In this regard, terrestrial infrastructure must also be a key focus.
Conclusion
The resilience of submarine cable infrastructure depends on an integrated approach that combines legislative measures, infrastructure investments, the development of European industrial capabilities and the strengthening of international cooperation.
Submarine cable infrastructure is a critical component of the European Union’s digital economy and security, as it supports nearly all international data flows and the operation of digital services. In this context, protecting and developing these infrastructures goes beyond the technical dimension, becoming a strategic priority with implications for economic security, technological autonomy, and the resilience of critical infrastructure.
Although the European Union has a legislative framework that is constantly being strengthened and significant expertise in the design, installation and maintenance of submarine cables, the existence of significant vulnerabilities cannot be ignored. These include dependence on non-EU actors for the development of new cable systems, the growing influence of hyperscalers on global transmission capacity, and existing dependencies in the supply chain for essential technological components.
At the same time, maintaining adequate capacity for the maintenance and repair of submarine cables is an indispensable element of the resilience of European infrastructure. Although the data analysed by experts indicate that the current emergency response fleet generally meets operational needs, the projected increase in the number of incidents and potential reductions in maintenance capabilities could affect response times and service continuity. In this regard, harmonizing authorization procedures and strengthening cooperation with third countries are necessary measures for increasing the effectiveness of interventions.