The Hidden Threat of the Baltic Sea Submarine Power Cables

Key Chapter Title List

1. Introduction
2. Current Status of Power Interconnection Infrastructure Development in the Three Baltic States
3. Power Supply, Demand, and Import Dependence in the Three Baltic States
4. The "Harmony Link" Cable Project and Energy Network Synchronization Planning
5. Spectrum of Diverse Threats Facing Submarine Power Cables
6. Deployment and Capabilities of Russian Naval Special Mission Forces
7. The Olenya Guba Naval Base and Its Special Mission Vessels
8. Activities and Potential Threats of the Russian Ship "Yantar"
9. Analysis of Three Hypothetical Scenarios of Cable Disruption on Baltic Energy Security
10. Assessment of Threat Impact Differences at Various Time Nodes
11. Compound Threat Risks in the Context of Hybrid Warfare
12. Future Challenges and Vulnerability Outlook for Baltic Energy Security

Document Introduction

In recent years, the vulnerability of transatlantic internet cables has sparked widespread discussion, while the security threats to submarine power cables in the Baltic Sea have not received equal attention. As a specialized research product of the NATO Energy Security Centre of Excellence, this report focuses on this neglected strategic issue, analyzing the potential threats posed by Russian naval forces to the region's energy infrastructure and their profound impact on the energy security of Estonia, Latvia, and Lithuania.

To break free from energy dependence on Russia and Belarus and integrate into the EU energy market, the three Baltic states have heavily invested in cross-border power interconnection projects over the past decades. They have established four key power corridors, including LitPol Link, NordBalt, EstLink-1, and EstLink-2, and plan to commission the "Harmony Link" cable in 2025 to achieve decoupling from the Russian-dominated BRELL ring network and synchronization with the continental European grid. However, their insufficient self-sufficiency in electricity (with a combined power deficit of 13.1 TWh in 2020) has led to increasing reliance on submarine cables, also introducing new security vulnerabilities.

The report systematically outlines the multiple threats facing submarine power cables, including conventional risks such as anchoring operations, trawling, and terrorist attacks, with a focus on analyzing the special mission capabilities of the Russian Navy. The fleet of vessels from Russia's Main Directorate of Deep-Sea Research (GUGI) deployed at the Olenya Guba naval base in the Barents Sea, including special mission ships of Project 22010 like the "Yantar," possesses the capability to carry deep-sea submersibles and unmanned vehicles for underwater engineering tasks such as cable cutting and listening device deployment. Their activities in key global maritime areas have raised concerns among many Western nations.

Based on scenario analysis, the report constructs three hypothetical scenarios to assess the impact of cable disruptions on Baltic energy security at different time nodes (pre-2025/post-2025) and under varying degrees of damage. The study finds that the short-term impact of a single or dual cable disruption is limited. However, after the three states disconnect from the BRELL ring network, especially when facing a hybrid warfare compound strike combining "physical attack + cyber attack," it could trigger large-scale grid disturbances, power supply shortages, or even widespread blackouts.

Although the probability of the most severe hybrid warfare scenario is low, Russia's continued investment in underwater military capabilities still makes Baltic submarine power cables a potential target in geopolitical competition. This report provides an authoritative risk assessment framework for NATO member states, policymakers in the three Baltic states, and energy security researchers, offering important reference for formulating targeted infrastructure protection and energy security assurance policies.