Committee on Security and Defence I
Cutting the Cord: Recent incidents in the Baltic Sea in 2023 and 2024 have seen undersea telecommunication cables, which carry over 95% of the world’s data traffic, as well as the crucial Balticconector gas pipeline be damaged by passing transport ships, sparking accusations of intentional sabotage and hybrid warfare efforts by China or Russia. What action should the EU take to ensure the integrity of its infrastructure, and limit the impact of hostile actions on its economy and security?
Executive Summary
The Baltic Sea has become a centre of attention for security after the 2022-2024 incidents where undersea telecommunication cables – carrying over 95% of global data traffic1 – and the Balticconnector gas pipeline were damaged. While some believe these incidents were caused by passing ships, they are also likely to have been acts of intentional sabotage by states like Russia or China. Such incidents threaten the security of the EU’s critical infrastructure, which is vital for the economy, energy security and digital networks.
The protection of undersea infrastructure in the Baltic Sea is restricted due to several reasons. Firstly, the Baltic nations show uncoordinated and inefficient security measures. Member States, such as Sweden, Estonia, and Germany, take individual actions based on national priorities rather than adopting a unified strategy. Secondly, Member States around the Baltic Sea have quite different financial resources and priorities. Thirdly, with cables and pipelines being located deep in the Baltic Sea, monitoring, securing, and repairing this infrastructure becomes a significant challenge.
As such incidents have been going on for a few years, several stakeholders have taken action to address these issues. The European Union Agency for Cybersecurity (ENISA) has developed cybersecurity frameworks and promoted risk assessments to protect critical infrastructure. North Atlantic Treaty Organisation (NATO) has significantly increased its presence in the Baltic region. In 2025, NATO member states announced the launch of the initiative “Baltic Sentry”, which is set to improve situational awareness and deter threats. The International Advisory Body for Submarine Cable Resilience is working to enhance the resilience of global communications infrastructure, emphasising timely repairs and damage mitigation. However, these efforts require greater coordination and integration to maximise their impact.
This committee is supported by the European Network for Cyber Security
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Introduction
In today’s world, which depends on constant connectivity and energy, infrastructure like undersea telecommunication cables and gas pipelines is more important than ever. However, recent incidents in the Baltic Sea show that this infrastructure is more fragile than we might think. The infrastructure, which carries the vast majority of the world’s data and the Balticconnector gas pipeline, had been damaged, supposedly by passing ships. These incidents have sparked a discussion about whether these incidents were just accidents or sabotage acts by Russia and China.2
As it concerns all European countries, not just the ones bordering the Baltic Sea, such incidents are not something to be ignored. The Balticconnector is responsible for transporting over 2.6 billion cubic metres of natural gas annually.3 While the 2023 incident did not disrupt the gas flow noticeably, there is no future guarantee of more significant incidents. At the same time, undersea cable traffic enables an estimated $10 trillion worth of financial transactions daily.4 Damage to these systems threatens not just infrastructure but the economy, energy security, and political stability of the EU.
Without immediate action, the EU risks leaving its infrastructure vulnerable to future attacks, whether accidental or intentional. Strengthening defences is not just a matter of maintenance – it is about safeguarding the economy and security. It raises the question – what steps should the EU take to address this growing threat and ensure the resilience of its critical infrastructure?
Fundamental Challenges
Lack of coordinated efforts among stakeholders
While countries individually are taking steps to ensure the decrease of hybrid warfare risks in the Baltic Sea, the actions are often isolated and focused on the country’s priorities and abilities. Sweden, Estonia, and Germany have taken some steps to protect the infrastructure in the Baltic Sea.5 6 7 While these actions are commendable, the lack of coordinated efforts leads to inefficient security measures, resulting in inefficiencies and delayed responses to threats.
Budgetary differences
The countries bordering the Baltic Sea differ widely in their ability to invest in critical infrastructure security. Economically advanced countries like Germany and Sweden have strong economies and high defence budgets to deploy advanced surveillance technologies and naval assets. In contrast, smaller countries such as Estonia and Latvia have limited resources yet have increased defence spending, making security one of the priorities but relying heavily on regional cooperation.
Technological limitations
The undersea infrastructure is located deep in the sea, in difficult-to-access areas, making continuous monitoring and protection almost impossible with current technologies. Detecting sabotage or damage is restricted due to the lack of cost-effective sensors and surveillance systems capable of operating in such areas. Moreover, as the incidents have shown, repairing cables and gas pipelines requires specialised equipment and personnel, are slow to deploy.8
Key Stakeholders
The European Union Agency for Cybersecurity (ENISA)
ENISA operates under the European Commission and collaborates with Member States, industry stakeholders, and various cybersecurity organisations to develop policies and frameworks to enhance critical infrastructure protection, including undersea cables and pipelines. ENISA does not have direct enforcement power or the ability to mandate security measures. Its role is advisory, and it needs cooperation both from national governments and private stakeholders in the implementation of measures. However, ENISA has already played a key role in establishing guidelines for securing critical sectors, promoting risk assessments, and facilitating the sharing of threat intelligence among Member States. It contributed to the development of the EU Cybersecurity Act, which strengthens the agency’s mandate and supports the creation of cybersecurity certification schemes for digital products, services, and processes. Additionally, it cybersecurity risks through the development of standards such as the Network and Information Systems Directive (NIS2).
North Atlantic Treaty Organisation (NATO)
NATO is a military alliance that provides collective defence against external threats. While its primary focus is military defence, private companies own and operate most of the undersea infrastructure. That means NATO can offer protection, surveillance, and deterrence, but its role in directly safeguarding civilian infrastructure is limited. Any action also needs to meet with political consensus among member states, some of whom might be reluctant to increase tensions with potential rivals. However, it has increased its military presence, conducted joint exercises, and reinforced security measures to deter potential attacks. NATO also facilitates cooperation between member states and the EU, helping integrate defence and cybersecurity efforts to protect critical infrastructure like undersea cables and pipelines.9
International Maritime Organisation (IMO)
IMO is responsible for setting global maritime safety standards, including regulations for protecting undersea cables and pipelines. The IMO operates under the United Nations and focuses on ensuring safety and security. It primarily focuses on preventing accidental damage to undersea infrastructure, leaving security matters to be handled by national governments, regional alliances, or military organisations such as NATO. However, IMO’s influence has limitations—it provides general safety and regulatory frameworks but does not have the mandate to directly address security concerns like intentional sabotage or military threats.
International Advisory Body for Submarine Cable Resilience
Recognising that submarine telecommunication cables are the foundation of global communications, transmitting most of the world’s internet data and enabling various services worldwide, UN-affiliated global digital and cable governance bodies have created an Advisory Body. Its task will be to explore ways to improve timely repair of the damaged infrastructure, minimise damage risks, and ensure uninterrupted communication.10 While it does not have direct enforcement powers, the International Advisory Body for Submarine Cable Resilience will raise awareness of vulnerabilities in undersea infrastructure through expert recommendations. However, compliance with recommendations depends on national policies.
Nordic-Baltic Eight countries
The Nordic-Baltic Eight Plus countries work together to address hybrid threats in the Baltic Sea. While these countries have a large interest in securing undersea infrastructure, their individual resources and capabilities vary. Despite that, they hold joint military exercises, such as Baltic Operations (BALTOPS) and Northern Coasts and improve cybersecurity through real-time information sharing, collaboration between Computer Emergency Response Teams (CERT), and research focused on protecting critical infrastructure.
Measures in place
The UN Convention on the Law of the Sea (UNCLOS)
Establishes the legal framework for protecting undersea infrastructure such as cables and pipelines, ensuring the freedom to lay them in the international waters and promoting cooperation. While it describes the penalties for damage, its scope is limited in addressing modern threats such as sabotage or hybrid warfare.
The European Union Maritime Security Strategy (EUMSS)
Specific measures include enhancing surveillance systems to detect and prevent threats and fostering intelligence-sharing among Member States. The strategy also prioritises deploying advanced technology to secure maritime infrastructure and calls for cooperation with NATO to counter hybrid warfare.
NATO efforts to safeguard underwater infrastructure
Following the 2024 damage to communication and power cables in the Baltic Sea, NATO has decided to safeguard important underwater infrastructure, reflecting the growing recognition from the member states of the importance of infrastructure. NATO will deploy 10 ships stationed near the energy and data cables to prevent future incidents. As of now, the ships are set to remain in the sea until April 2025.11
Baltic Sentry
On 14th January 2025 in Helsinki, leaders of NATO member states bordering the Baltic Sea12 agreed to launch “Baltic Sentry” vigilance activity to improve maritime situational awareness and prevent future hostile activities.13 While nothing specific has yet been agreed upon, the NATO Maritime Centre for Security of Critical Underwater Infrastructure (NMCSCUI) is tasked to help Allied Command Operations and NATO Allies in the decision-making process as well as coordination of actions aimed at undersea infrastructure protection.
ARTICLE IN THE BLOG OF THE CARNEGIE EURASIA CENTER
Securing Europe’s Subsea Data Cables
Historical context
Russia’s disagreement with Ukraine about gas resulted in disrupted energy supplies in 17 European countries, showing the reliance on Russian gas pipelines.14
Russia annexed Crimea, while also increasing its hybrid warfare tactics: cyberattacks, disinformation, and sabotage against Europe’s critical infrastructure, including infrastructures in the Baltic Sea region.
The Balticconnector gas pipeline began to operate between Finland and Estonia, reducing Finland’s reliance on Russian gas and connecting Finland to the rest of Europe.
Three out of four Nord Stream gas pipelines in the Baltic Sea were damaged by explosions. The damage was discovered in several places at once, suggesting that the incident was most likely sabotage rather than a simple accident. Although no arrests had been officially made as of January 2025, German authorities issued a European arrest warrant in June 2024 for a Ukrainian who is thought to have committed this act of sabotage.15
The operating companies observed a sudden drop in the Balticconnector gas pipeline pressure from 34.5 bar to 12 bar and later to 6 bar.16 They closed the valves, stopping the gas flow. Later they detected a leak from the damaged pipe and, in the following days, also discovered that a communication cable had been damaged intentionally.
Two submarine communications cables—the BCS East-West Interlink and C-Lion1 fibre-optic cables—were damaged in the Baltic Sea. Hybrid warfare and sabotage were suspected, so the investigation began on a Chinese cargo ship’s potential involvement at the request of Russian intelligence.17
The power cable of Estlink-2 and some communication links between Finland and Estonia were damaged. The Russian-linked oil tanker Eagle S, believed to be part of Russia’s “shadow fleet,” is suspected of dragging its anchor to cause the damage.18
An undersea fibre optic cable between Sweden and Latvia was damaged. While the circumstances are being investigated, officials report that this was most likely caused by external influence.19
WORKING PAPER BY The European Centre of Excellence for Countering Hybrid Threats
Russia’s hybrid threat tactics against the Baltic Sea region: From disinformation to sabotage
Outlook
Although it may seem that this topic primarily impacts only the countries bordering the Baltic Sea, its influence extends globally as it intersects with modern geopolitics, technology, and the threats of hybrid warfare. Recent incidents have revealed a hard truth: the systems that support our economies and connect people are more fragile than we might realise.
Therefore, I invite you to delve deeper into the topic. When researching it on your own, consider how the EU can create a unified approach to securing our shared future. Are recent efforts enough to secure the undersea infrastructure long-term, or are they just temporary fixes? How should the EU and NATO divide responsibilities? Should the EU develop independent defence capabilities for undersea assets? How do economic interests, like dependence on foreign technology or investment in critical infrastructure, complicate efforts to build a unified European security strategy? How and whether should private companies, such as energy and telecommunications providers, be more directly involved in security efforts?
As you explore the topic further, do not forget to consider the more profound implications: What could be the cost of inaction for global security? How can we ensure that collaborative efforts to secure these infrastructures do not fluctuate under political or economic pressures seen in the world?
FOOTNOTES
- CNN (2025). Ships, sea drones and AI: How NATO is hardening its defense of critical Baltic undersea cables Link ↩︎
- Atlantic Council (2024). Suspected sabotage by a Chinese vessel in the Baltic Sea speaks to a wider threat. Link ↩︎
- CNN (2023). Suspected sabotage shuts another European gas pipeline.Link ↩︎
- Al Jazeera (2025). NATO launches new Baltic Sea mission to protect undersea cables. Link ↩︎
- AP News (2025). Sweden to contribute up to 3 warships to reinforced NATO presence in the Baltic. Link ↩︎
- AP News (2025). Estonia steps up patrols in the icy Baltic Sea in a show of force after suspected cable sabotage. Link ↩︎
- Internationale Politik Quarterly (2025). The Underwater Battlefield: Protecting Submarine Critical Infrastructure. Link ↩︎
- Reuters (2023). Repairing Finland-Estonia gas pipeline may take months. Link ↩︎
- WindEurope (2024).NATO determined to protect critical undersea energy infrastructure. Link ↩︎
- International Telecommunication Union (2024). Launch of international advisory body to support resilience of submarine telecom cables. Link ↩︎
- Politico (2025). NATO sends a fleet to guard Baltic Sea cables. Link ↩︎
- Finland, Estonia, Denmark, Germany, Latvia, Lithuania, Poland and Sweden ↩︎
- NATO (2025) Joint Statement of the Baltic Sea NATO allies summit. Link ↩︎
- Oxford Institute for Energy Studies (2009). The Russo-Ukrainian gas dispute of January 2009: a comprehensive assessment. Link ↩︎
- The New York Times (2024). Germany Issues Arrest Warrant for Ukrainian Over Nord Stream Explosion. Link ↩︎
- Offshore Technology (2023). Finland-Estonia Balticconnector gas pipeline shut down after suspected leak. Link ↩︎
- The Guardian (2024). Two telecoms cables in Baltic Sea severed, raising suspicions of sabotage. Link ↩︎
- Reuters (2024). Finland boards oil tanker suspected of causing internet, power cable outages. Link ↩︎
- The Guardian (2025). Sweden opens inquiry into damaged undersea cable as Nato deploys ships. Link ↩︎