Hybrid Warfare Under Water: Threats to the Baltics and Lessons for Ukraine

On December 25, when the Christian world celebrated Christmas, in another world, missiles and drones were targeting the energy infrastructure in Ukraine and at this time preparations for the operation in the Baltic were being completed. A tanker, which dropped anchor on the seabed while underway, severed the EastLink-2 underwater high-voltage electrical cable, which connects the power systems of Estonia and Finland across the Gulf of Finland.

EastLink and BRELL

EastLink-2 is a high-voltage cable for transmitting 650 MW of direct current, which was built in 2014 and has a total length of about 170 km. Of these, 145 km run along the bottom of the Baltic Sea, 14 km is a high-voltage overhead line in Finland and 12 km is an underground high-voltage cable in Estonia. This is the second project in the framework of the development of an electricity connection between Finland and Estonia, which should contribute to increasing the energy independence of the Baltic countries and their decoupling from the post-Soviet energy ring BRELL (Belarus, the Russian Federation including the Kaliningrad region, Estonia, Latvia and Lithuania). EastLink-1 was laid in 2007 slightly further west and has a capacity of 350 MW. The cable for the EastLink-2 project was manufactured by the experienced offshore power infrastructure company Nexans (Norway), and was laid on the bottom of the Baltic Sea by the specialized vessel Nexans Skagerrak. Until 2024, it was considered one of the most reliable submarine cables in the region. On January 26, 2024, EastLink-2 ceased operation due to technical problems in the coastal area of ​​​​Estonia. Namely, the reason for the termination of its operation was the depressurization of the connection of the submarine cable with the coastal section, and it fully resumed operation almost eight months later. This happened on September 12. The restoration of the functionality of the cable connection of the power systems of Estonia and Finland was of great importance on the eve of the decisive stage of preparation for the disconnection of the Baltic countries from the power system of the Russian Federation, scheduled for February 8, 2025.

“Suddenly” on December 25, EastLink-2 was put out of action. As it soon became clear, for a long time. This was done according to an already proven scheme: the civilian oil tanker EAGLE S, registered in the Cook Islands, with a Russian crew, moving in the Baltic Sea perpendicular to the EastLink-2 cable, tore this interconnector with its anchor. It is worth noting that this scenario is practically a carbon copy of similar “operations” in the Baltic on November 18, 2024 (rupture of fiber optic cables between Lithuania and Sweden and between Finland and Germany) and October 7, 2023 (rupture of the Balticconnector gas pipeline and the Elisa fiber-optic communication line between Estonia and Finland). According to preliminary estimates by the Finnish transmission system operator Fingrid, repair work on the damaged section in the sea will last several months, in fact until the summer. The Nord Pool trading platform, where wholesale electricity trading operations using EastLink-2 capacities take place, noted in its notifications to the bidders that this intersection was excluded from future operations due to unforeseen circumstances at least until the end of July 2025. It is worth noting that the loss of 650 MW of capacity negatively affects the functioning of the energy system both in Finland and to a much greater extent in Estonia and neighboring Latvia and Lithuania.

The increase in the share of renewable energy sources increases the importance of cross-border interconnectors for balancing the energy systems of even fairly large European countries. Finland uses EastLink-2 in cases where its own energy capacities cannot meet the demand for electricity due to a combination of several factors, for example, at low temperatures in the winter period with dense cloud cover and no wind. The use of interconnectors in such cases helps to maintain the frequency in the network, and also minimizes price jumps on the spot market. In December 2024, Finland imported about 25 GWh of electricity, while Estonia imported more than 530 GWh, part of which also went to neighboring Latvia and Lithuania.

Therefore, the decommissioning of EastLink-2 will affect the electricity market of all Baltic countries, as this cable provided about two-thirds of the imported capacity from Finland, contributing to the stability of prices and technical parameters of the power system. It is worth noting that currently only one interconnector, EastLink-1, with a capacity of 350 MW, remains in operation, which was put into operation back in 2007.

Synchronization in question?

The active use of EastLink-2 for electricity imports allowed Estonia, Latvia and Lithuania to prepare for disconnection from the power system of the Russian Federation on February 8, 2025, when the current agreement within the framework of the BRELL energy ring expires. In particular, it was possible to form energy reserves, test power generating capacities in different operating modes to maintain frequency and voltage in the power system, maintain, repair and promptly replace equipment that showed signs of unreliability. The ultimate goal is to synchronize with the continental European ENTSO-E power system.

Without EastLink-2, Estonia is forced to put its own power generation into operation to the maximum. It is worth noting that the cost of electricity on the spot market has increased significantly, despite the lack of significant demand from the commercial sector due to the holiday weekend period. A similar situation, albeit to a lesser extent, is observed in Latvia, which has also started to partially supply electricity to Estonia to cover certain peak consumption periods.

In addition, there is a deadline for synchronization with ENTSO-E, several months of the heating season with variable weather conditions without EastLink-2, the risks of a significant electricity shortage and a significant increase in spot prices. Already in the first days after the EastLink-2 damage, Estonia began importing Russian electricity from the Leningrad region with a capacity of 200–300 MW at certain hours. The situation may become even more complicated with the return of business to active work in the first half of January 2025 and a likely decrease in temperature.

It is worth noting that despite the difficult situation, the Baltic countries are determined to continue preparations and disconnect from the Russian Federation's power system in February 2025. The main element for ensuring the physical connection between the Baltics and the European Union will be the LitPol Link land interconnector, which connects Poland with Lithuania, provides the possibility of transmitting electricity with a capacity of 500 MW and passes through the so-called Suwalki corridor.

Thus, it is quite obvious that the Baltic states are waiting for intensive negotiations with ENTSO-E, Poland and Finland, and review and finalize the scenarios for the operation of the power system in different modes. At the same time, new “accidents” cannot be ruled out, because the Russian Federation will try to retain energy control over the region in which the Kaliningrad region is located and to which part of the electricity is still supplied in transit through Latvia and Lithuania. In Estonia, for example, the Estonian and Baltic power plants are located practically on the border with the Russian Federation and, accordingly, risk becoming the object of a hybrid attack.

The Ukrainian experience of synchronization with ENTSO-E gives grounds for optimism that security factors will be taken into account, and the Baltic states as members of the European Union and the North Atlantic Treaty Organization will be connected to the power system of continental Europe without unnecessary restrictions.

At the same time, the regional market consisting of the Baltic countries and Poland will temporarily become more energy-deficient, spot prices for electricity will increase and competition for the availability of the resource will intensify. Given this situation, Ukraine should offer its own expertise and experience in managing the power system in the first days of its operation in an isolated mode and after unification with ENTSO-E. In addition, further cooperation should also be discussed in the context of limited available energy capacity, the conditions for continuing commercial operations and providing emergency assistance. An attempt to prevent the Baltics from disconnecting from BRELL is one of Moscow's hidden intentions, which will lead to the opposite effect, namely, such actions will only strengthen the determination of Tallinn, Riga and Vilnius to break with the energy system of the Russian Federation. It is also important to pay attention to other aspects of the hybrid operation on the Baltic Sea.

The Stage of Nuclear Escalation

For some reason, little attention is paid to the product entitled “Recommendations for Strengthening the Deterrence Strategy in the Conflict in Ukraine. Stages of Escalation” by Kremlin (non-staff) political scientists Dmitri Trenin, Sergei Karaganov, and former Pacific Fleet commander Sergei Avakyants. All of them are apologists for the use of nuclear weapons. The recommendations include not only the task of striking Western troops if they enter the territory of Ukraine, the destruction of drones and other aircraft of the North Atlantic Treaty Organization over the Black Sea, the disabling of reconnaissance spacecraft of the United States of America, as well as much more decisive actions. The recommendation on “the gradual cutting of submarine cables, first in the Baltic Sea, then in the Atlantic, with a demonstration to the enemy of military-technical capabilities for such actions” is especially striking. On November 11, Putin’s aide and head of the Russian Maritime Collegium, Nikolai Patrushev, “predicted” the likelihood of emergency events with underwater fiber-optic cables.

Which, in fact, happened on November 17-18, when the Chinese dry cargo ship Yi Peng 3 tore the BSC East-West Interlink fiber-optic cables between Sweden and Lithuania, and the C-Lion1 between Finland and Germany. When a joint German-Finnish statement was made on November 19 that the parties were “deeply concerned about the torn submarine cable,” that “our European security is under threat not only because of Russia’s aggressive war against Ukraine, but also because of the hybrid war of the aggressors,” politicians in the Kremlin, we assume, laughed at it. There, they were once again pleased that the Europeans did not call them “thieves,” saying that what was the Russian Federation doing here, since the ship was Chinese, ignoring the fact that its pilot was an experienced Russian captain.

And on November 29, Moscow let the so-called “threatening” Deputy Foreign Minister Sergei Ryabkov speak, so that he could once again interpret the Kremlin’s messages to the West in his characteristic manner: “I hope that our signals, both verbal and material (emphasis added. — Author’s note), are still perceived by at least someone somewhere, in some corridors of power, in some offices, in some American bunkers, and not just rejected as some kind of propaganda.”

On December 25, Moscow decided to explain once again to Europe and the United States of America what “material consequences” the signals from the Kremlin would have by launching the tanker on a special flight. It is worth noting that the Russian Federation has been deeply concerned by the rather more determined than previously planned sanctions against its so-called shadow oil export fleet. On November 25, the British government decided to impose sanctions on 30 vessels “responsible for transporting billions of pounds worth of oil and petroleum products.” And on December 16, at a summit of leaders of the Joint Expeditionary Force in Tallinn, 12 countries of the Baltic Sea region, the Netherlands, the United Kingdom and Iceland agreed to introduce measures to deter the Russian tanker fleet, and on the same day the Council of Ministers of the European Union adopted the 15th sanctions package, targeting, among other things, oil tankers.

So, the pieces of the puzzle are coming together. The Kremlin probably wanted to fire a “warning shot” at Poland, which took over the presidency of the European Union in the new year and is known in the European Union for its decisive and strict attitude towards the Russian Federation. It is worth taking such a strict side in this issue because something else could happen to the SwePol power cable connecting Sweden with Poland (capacity 600 MW), or the Baltic pipe gas pipeline for transporting Norwegian gas to Poland, or to the LNG terminal in Świnoujście or the oil port in Gdansk.

The next six months will see an intensification of the war, which will cause great concern in the Baltic theater of military operations. Who will win — the consolidated political will of the countries of the region and the transition from rhetoric to practical actions to block Russian oil traffic, or the Kremlin's strategy of escalation and intimidation that has been ongoing since October 2023?