The New EU Action Plan for Submarine Cable Security

Stretching thousands of kilometers across the ocean floor, submarine cables are the primary communication highways of modern civilization, carrying nearly all intercontinental internet traffic and ensuring vital energy connections between states. However, despite their strategic importance, these critical infrastructures face growing risks, from accidental damage to deliberate attacks. In response to this threat, the European Union has launched an ambitious plan to strengthen their security, ensuring that Europe’s digital and energy infrastructures remain resilient in an increasingly volatile global landscape.

The EU Action Plan for Cable Security[1], presented in February 2025, sets out a clear strategy to protect these critical infrastructures. In recent years, the number of incidents involving submarine cables has intensified, ranging from fishing-related accidents and anchor drags to targeted sabotage by hostile actors. Recent disruptions in the Baltic Sea have underscored the need for stronger protection, especially as these attacks may be part of broader hybrid warfare campaigns aimed at destabilizing the region. The EU’s plan focuses on four main areas: prevention, detection, rapid response, and deterrence.

The first step is prevention[2]. By strengthening existing cybersecurity regulations, (as a legal and security framework) particularly through the NIS2 Directive[3] and the Critical Entities Resilience (CER) Directive[4], Member States will be required to enhance the resilience[5] of their submarine cable networks[6]. This involves not only protecting the physical infrastructure but also reinforcing cybersecurity defenses. At the same time, the EU is making significant investments in alternative cable routes and smart cables, which will be equipped with sensors to detect unusual activity in real time. These advancements will ensure that any disruptions can be identified and mitigated before they escalate into large-scale crises.

However, prevention alone is not enough. The plan also highlights the need for improved detection. Currently, no single entity has a complete picture of what is happening around Europe’s vast network of submarine cables. To address this gap, the EU is developing an Integrated Surveillance Mechanism[7], which will combine satellite imagery, naval intelligence, and AI-driven monitoring tools across multiple layers to provide real-time alerts on potential threats. In addition, the EU is intensifying cooperation between maritime agencies, cable operators, and national security bodies to improve data sharing and response times – to report incidents in real-time.

When incidents occur, a fast and coordinated response is essential. The EU is tackling this challenge by establishing an EU Cable Vessels Reserve Fleet, a dedicated group of specialized vessels capable of repairing damaged cables, even under extreme weather conditions. At the same time, coordination between the EU Critical Infrastructure Blueprint[8] and the Cybersecurity Blueprint[9] is being reinforced to ensure a holistic response to both physical and cyber threats. This alignment enhances crisis management efforts, strengthens intelligence-sharing mechanisms, and ensures a unified strategy to safeguard submarine cables against hybrid attacks. This will be complemented by a stockpile of essential spare parts, strategically positioned to ensure rapid deployment when needed. At the same time, stronger partnerships with NATO and other international allies will enhance Europe’s ability to respond to both cyberattacks and physical damage to its underwater infrastructures.

Finally, the EU is making it clear that attacks on submarine cables will not go unanswered. The Action Plan strengthens the Hybrid Toolbox[10], a set of measures designed to hold malicious actors accountable through diplomatic, economic, and legal consequences. A key part of this effort is tackling the so-called shadow fleet, a network of unregistered or suspiciously operated vessels that may have been involved in recent acts of sabotage. By tightening regulations and increasing cooperation with global maritime organizations, the EU aims to ensure that hostile actions against its critical infrastructure carry real consequences.

In this way, the EU Action Plan for Cable Security is not just a technical response—it is a strategic move to protect Europe’s sovereignty and stability in an increasingly unpredictable world. Through a combination of cutting-edge technology, international collaboration, and decisive policy measures, the EU is taking the lead in safeguarding the invisible networks—critical infrastructures—that keep the modern world running.

By José Amaro

[1] EU Action Plan for Cable Security: https://digital-strategy.ec.europa.eu/en/library/joint-communication-strengthen-security-and-resilience-submarine-cables | https://digital-strategy.ec.europa.eu/en/library/report-cybersecurity-and-resiliency-eu-communications-infrastructures-and-networks

[2] “[…] to reduce the number and impact of disruptive incidents and make it more difficult for any malicious actor to put the security of the Union at risk.”

[3] NIS2 Directive: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32022L2555

[4] Critical Entities Resilience (CER) Directive: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32022L2557

[5] The Commission has also taken a more focused approach to submarine communication cables through its Recommendation on Secure and Resilient Submarine Cable Infrastructures (https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32024H0779#:~:text=The%20national%20cybersecurity%20strategy%20of,highest%20level%20of%20their%20protection). This Recommendation establishes an EU-wide strategic policy framework to evaluate risks associated with these critical infrastructures and outline appropriate mitigation measures. It calls for the Commission and Member States to conduct a comprehensive mapping and analysis of both existing and planned submarine cable infrastructures, along with regular, consolidated assessments at the Union level to identify risks, vulnerabilities, and dependencies.

[6] To strengthen the effectiveness of these broad security frameworks, it is crucial that all stakeholders involved in improving the resilience of submarine cables follow consistent and coordinated security measures across all Member States. The Commission, therefore, urges Member States to ensure that national laws implementing the NIS2 framework apply to all operators of submarine communication infrastructure. Additionally, beyond their legal responsibilities under the CER Directive, Member States should integrate entities providing essential services for submarine electronic communications and electricity transmission into their strategies for strengthening critical infrastructure resilience. This includes incorporating them into risk assessments for essential services and formally recognizing key infrastructure operators as critical entities. The swift and complete implementation of these legal frameworks should be an immediate priority for all Member States.

[7] Linking EU agencies (EMSA, Frontex, SIAC, CISE).

[8] EU Critical Infrastructure Blueprint: https://www.consilium.europa.eu/en/press/press-releases/2024/06/25/critical-infrastructure-blueprint-for-protecting-eu-citizens-and-the-internal-market/

[9] Cybersecurity Blueprint: https://digital-strategy.ec.europa.eu/en/library/cyber-blueprint-draft-council-recommendation

[10] Framework designed to counter hybrid threats, including sabotage, disinformation campaigns, and cyber-attacks that target critical infrastructure, such as submarine cables. https://www.consilium.europa.eu/en/policies/hybrid-threats/