Foreign military ships must notify their passage through the narrow Gulf of Finland at least 48 hours in advance. This is the only access to the Russian port of Saint Petersburg. Estonia summoned the Russian chargé d'affaires and delivered a formal protest.
Foreign Minister Margus Tsahkna called the violation serious and unacceptable. Earlier this year, tensions flared after Estonia tried to intercept a Russian oil tanker. Russia responded by deploying a fighter jet that violated Estonian airspace.
In the Baltic Sea and other Scandinavian waters, several maritime incidents have occurred in recent months. It began in October 2023. At that time, the gas pipeline between Finland and Estonia suddenly lost pressure. A ship flying the Chinese flag with Russian ties dragged its anchor kilometers along the seabed, damaging the pipeline.
A year later, a similar event happened again. In October 2024, another ship under the Chinese flag broke two underwater cables using the same towing method. European intelligence services suspected that the crew had been bribed by Russian agencies. This time, Estonia stopped the ship.
The escalation peaked on Christmas Day 2024. The Eagle S, a tanker from the Russian "shadow fleet," dragged through five separate underwater cables at once. Finnish special forces boarded the Eagle S in international waters and forced the ship to a Finnish port. For the first time, a crew was detained.
NATO warships and patrol aircraft then began permanently monitoring the Baltic Sea. The cable incidents ceased immediately.
Although the confrontations between ships have somewhat cooled down since, a new threat has emerged: espionage drones. Dozens of incidents with anonymous drones flying over critical (military) infrastructure, such as chemical plants and military sites, have persisted.
Western intelligence agencies suspect these drones are launched from Russian ships in the Baltic Sea. This hybrid warfare is not fought on a traditional battlefield, but in the gray area of international law, with merchant ships as weapons and plausible deniability as defense.