Almost all intercontinental internet traffic—including email, financial transactions and data processed by artificial intelligence—travels over optical cables laid on the seafloor. With the spread of AI and expanded cloud services, cross‑continent data flows have surged: the aggregate international transmission capacity of European Union submarine cables rose from 318 Tbit/s in 2010 to 3,755 Tbit/s in 2024. Industry forecasts expect demand for global data traffic to grow by about 24% per year on average over the next decade.
Although satellite internet often draws attention, 97–98% of international data still traverses submarine optical cables. There are roughly 700 communications cables connecting continents, totaling about 1.5 million kilometres. Physically many of these cables are thin—often no thicker than a garden hose—yet they form the critical infrastructure of the global digital economy.
Technological shift and capacity concentration
New high‑capacity systems rely on Space Division Multiplexing (SDM): instead of increasing load on individual fibres, SDM increases the number of fibre pairs in a cable. This delivers higher aggregate throughput and better energy efficiency, but it also concentrates capacity. In the EU the newest 31 cables now provide about 74% of total international transmission capacity, while the oldest 91 cables account for just 2%.
Rising traffic requires both new cable systems and continual renewal of existing infrastructure. Although a submarine optical cable has a planned service life of roughly 25 years, many systems are retired sooner because they cannot meet new-generation transmission demands.
Who owns the cables? Hyperscalers take the lead
Submarine cable projects remain largely market-driven. Where multinational telecom consortia once funded new international links, investment is increasingly coming from Google, Meta, Microsoft and Amazon—so‑called hyperscalers that operate global data centre and cloud infrastructures. For these companies cables are not standalone businesses but foundational infrastructure for cloud services and AI.
Hyperscalers have the balance sheets to finance projects that are prohibitively expensive for traditional telecom operators. As a result, on transatlantic routes the four American hyperscalers now control roughly 90% of available transmission capacity, and globally they account for nearly three quarters of submarine optical network capacity.
This ownership shift shapes network development: routes, capacities and investment priorities are increasingly driven by hyperscalers’ operational needs. Google, for example, is involved in more than thirty submarine cable projects worldwide.
China’s growing role and geopolitical competition
Submarine cable development has become an arena of great‑power technological rivalry. China has expanded its presence in international cable projects as part of the Digital Silk Road, notably in Asia, Africa, the Middle East and Latin America. HMN Technologies is one of the four major global submarine cable system integrators and participates in many design, manufacturing and deployment projects.
The United States has reacted by curbing Chinese participation in some cable projects for national security reasons; several projects initially involving Chinese partners were restructured or excluded. Consequently, selection, financing and ownership of cable projects are increasingly influenced by geopolitical and security considerations as well as market logic.
Europe’s industrial strengths — and limited strategic control
On the industrial side, Europe remains significant. Alcatel Submarine Networks (ASN) accounted for about 34% of the global market by cable length installed between 2020 and 2024. Orange Marine is an important international operator for deployment, repair and maintenance. Together these two firms operate twelve specialised cable ships. Manufacturers such as Prysmian and Nexans, and several European telecom operators, also play leading roles across the cable life cycle.
Yet Europe lacks a unified, transparent registry of cable ownership, funding, capacity allocation and strategic dependencies. Unlike the United States, where the Federal Communications Commission (FCC) mandates detailed reporting for each international cable, the European Union has no binding common reporting system. There is also no permanent EU body coordinating strategic planning, risk assessment and crisis response for submarine cables.
Risks, incidents and limited repair capacity
Incidents in the Baltic Sea and elsewhere changed Europe’s view of undersea infrastructure: protection of submarine assets is now framed as economic security and a geopolitical concern. Still, a realistic assessment matters: globally there are about 150–200 cable faults annually, and the vast majority are caused by fishing gear, ship anchors, submarine landslides or other natural causes rather than deliberate sabotage.
Network vulnerability largely stems from structural concentration: a significant share of traffic traverses a few high‑capacity systems and geographic chokepoints. The Red Sea is a notable example, carrying roughly 90% of data traffic between Europe and Asia; simultaneous damage to multiple links in a single region could cause serious disruption if geographic redundancy is insufficient.
Repair capacity is also constrained: only 63 specialised cable ships are available worldwide, many in an ageing fleet. In a larger regional incident, recovery time depends not only on damage extent but also on ship availability, suitable port infrastructure and the speed of permitting procedures.
EU policy responses and financing
The European Union issued a recommendation on submarine cable security in 2024 and followed with a 2025 action plan. The approach reframes cable security as part of critical‑infrastructure resilience: common risk assessments and stress tests, mapping of strategically important networks, improvement of maritime situational awareness, and support for shared repair and recovery capacities are among the measures.
Financially, the EU’s Connecting Europe Facility (CEF) Digital programme is a key tool. Between 2021 and 2027 CEF Digital allocates €2.07 billion for digital connectivity; projects related to submarine cables have received about €420 million so far, and an additional €542 million is earmarked for 2025–2027. While meaningful, these amounts remain far below investments made by major technology companies.
The article argues that if the EU treats submarine cables as strategic infrastructure, regulatory requirements must be complemented by co‑financing and risk‑sharing instruments, plus the establishment of a permanent European coordination body and a mandatory data reporting system to make ownership, capacity, financing and incident data transparent.
Conclusion: an interconnected challenge beyond security
Submarine optical cables are simultaneously technical, commercial and geopolitical issues. Digital sovereignty does not rest solely on owning cables; it depends on the ability to integrate cables, data centres, cloud platforms and AI infrastructure into a competitive digital ecosystem. Europe has industrial and deployment capabilities, but to strengthen strategic influence it needs a comprehensive EU strategy that aligns security, industrial and digital infrastructure policies, improves financing and governance, and manages geopolitical risks while addressing the dominance of hyperscalers.
