Underwater warfare in the Baltic: Why is Russia targeting the critical infrastructure of EU and NATO countries?

In almost every incident, investigators suspect deliberate actions by the Russians. The latter consistently deny everything: "You try to prove it."

Why might the Kremlin be behind the diversions in the Baltic Sea? Are there risks of an increase in the number of diversions, and how can we counter hybrid aggression?

Diversions in the Baltic Sea

Since the beginning of the large-scale war, there have been four glaring incidents involving the critical infrastructure of NATO and European Union countries in the Baltic Sea.

The first occurred in October 2023: the Baltic Connector gas pipeline and the data transmission cable connecting Estonia and Finland across the Gulf of Finland were severed. The main version from the Finnish National Bureau of Investigation suggests that this is linked to the Chinese vessel Newnew Polar Bear. Its anchor, which was later retrieved from the seabed, caused the damage. This incident is still under investigation.

Initially, the emergency was attributed to coincidence, as it was the first such case. However, in November 2024, it happened again. The Chinese vessel Yi Peng 3, which departed from the Russian port of Ust-Luga on November 15, severed two communication cables: one between Sweden and Lithuania and another between Germany and Finland.

Swedish police investigators believe that the captain of the vessel, which dragged an anchor along the seabed for over 160 km, may have acted under the direction of Russian special services. Additionally, there were citizens of the Russian Federation among the crew. "This alarmed everyone in the region. It is worth noting: the Naval Forces promptly detained the vessel. Investigative actions are ongoing," says Mykhailo Honchar, president of the Globalist Center "Strategy XXI".

Even in this case, some referred to the new incident as a coincidence. However, when it happened for the third time on December 25, this time involving the power cable EstLink 2 between Estonia and Finland, everyone understood: this is not a coincidence. Repair of the 650 MW cable will take over seven months – at least until the end of July.

However, this case was not the last. At the end of January 2025, an underwater communication cable connecting Latvia and Sweden was damaged. The cable was struck by yet another Chinese vessel, Vezhen, which also departed from the Russian port of Ust-Luga.

The shipowner confirmed that his tanker was responsible for the incident, but assured that it was unintentional. It was claimed that one of the several-ton anchors fell to the seabed due to strong winds and snagged the fiber optic cable. The vessel was detained and directed to Swedish territorial waters for investigation.

Look for who benefits

Many investigative bodies and EU politicians have expressed the theory of possible Russian involvement in the aforementioned diversions.

"There should be no doubt about who did this. Of course, investigations will continue, and it will be a long process. Some individuals may have doubts: is it a deliberate diversion or a coincidence? The Russians, in their typical manner, say: 'You prove it.'

This has alarmed many responsible figures in the EU and NATO, leading to consultations. These covert actions by the Kremlin can be seen as a warning to the countries of the region, the EU, and NATO that these are just isolated instances of communication disruptions, and it could get worse. Imagine if such actions become widespread," says Honchar.

He suggests that this could be a specific type of Russian-Chinese cooperation.

"I leave a certain percentage of probability that the Russians are using the Chinese 'in the dark,' because the actions are carried out not by the shipowner but by people from the crew. Often, Russians work on these vessels, and not just ordinary sailors, but captains or first mates. Therefore, this could be a form of cooperation where each plays their role," adds the expert.

During one of the press conferences, journalists asked Kremlin leader Vladimir Putin about the possible involvement of Moscow in the diversions in the Baltic, to which the Russian leader responded that it was "nonsense".

"Anything could have happened... There, technologically... They could have snagged with a hook, I don't know, there... There could have been an earthquake, it happens rarely but can occur. Some kind of landslide... I don’t know, let them investigate," Putin justified.

Why the Baltic and who’s next

A large portion of Russia's oil and petroleum products export is carried out through its terminals in the Black and Baltic Seas.

Regarding the Black Sea, Russia is less concerned about energy resource exports, as they have a somewhat unpredictable but generally stable ally – President Recep Tayyip Erdoğan of Turkey.

In the Baltic region, however, discussions in 2024 revolved around limiting Russian oil traffic, which began to threaten the environment. This is due to the fact that in recent years, Moscow has loaded the Baltic Sea with a massive volume (up to 100 million tons per year) of oil and petroleum products, which are hazardous cargoes, without consultations.

What consequences this may have, considering the use of outdated tankers without insurance, was demonstrated by the case of the accident involving two vessels near the Kerch Strait.

"Recently, there has been talk in the Baltic about the need to limit oil traffic. Especially since it comes from an aggressor country that finances the war with this money. This is why Russia has begun offensive actions in the Baltic region. It has felt that the end may be near for its oil empire," believes Honchar.

In the North Sea, adjacent to the Baltic, the density of critical underwater communications is higher. Particularly considering that many offshore wind farms have emerged in the shallow waters of the North Sea in recent decades. Their total capacity is estimated at 25 GW, equivalent to 25 nuclear power units. For context: peak consumption in Ukraine in recent years has been below 20 GW.

A large number of power cables, through which electricity is delivered from wind farms to the shore, run along the seabed of the North Sea. Therefore, through its diversions, Russia is projecting a scenario of what could happen if the Baltic countries impose significant restrictions on Russian oil traffic.

Likewise, this could serve as a warning to Poland, which began its presidency in the Council of the European Union on January 1, 2025.

For instance, the power cable with a capacity of 600 MW connecting Sweden and Poland, or the underwater gas pipeline Baltic Pipe between the Norwegian sector of the North Sea and Poland, could be damaged, which has allowed Warsaw to diversify its gas supply and move away from Russian gas.

Additionally, Poland plans to build one of the largest offshore wind farms in the world in the Baltic Sea, which will provide energy for 2.5 million households.

The recent events in the Baltic may only be the beginning, and if no countermeasures are taken soon, the number of incidents could increase.

How to counter diversions

NATO countries are already enhancing monitoring, patrolling, and tracking of all vessels in the Baltic Sea. This is a positive step, but it is impossible to attach sensors or place guards on boats for every kilometer of underwater communications. It's costly and inefficient. Honchar suggests three options to compel the Russians to stop destroying critical infrastructure.

The first – mirror actions are needed. Something similar should occur with critical infrastructure on Russian territory. However, Russia is a continental state, and most of its critical infrastructure is located within the country.

The second</