Estonia-Russia relations

Estonia has announced it will no longer permit vessels to transit through Russian territorial waters following the detention of the oil tanker Green Admire by Russian authorities over the weekend. The decision comes amid rising tensions in the Baltic Sea and increased scrutiny of Russia’s so-called shadow fleet.

The Green Admire, a Liberian-flagged tanker owned by Greece’s Aegean Shipping, departed the Port of Sillamäe on the evening of 17 May carrying a cargo of shale oil bound for Rotterdam. The vessel was sailing along a previously agreed route that crosses Russian waters in the Gulf of Finland – a corridor established between Estonia, Finland and Russia to enable safe passage for large vessels around Estonia’s shallow coastal zones.

Shortly after midnight, in the early hours of 18 May, Russian authorities intercepted the tanker and instructed it to proceed to Gogland Island (Suursaar), where it has remained at anchor since 04:00. The Estonian Transport Administration confirmed the incident and stated that no similar detentions had occurred previously under the long-standing navigational agreement.

In response, Estonian Foreign Minister Margus Tsahkna confirmed that ships travelling to and from Sillamäe will now be directed solely through Estonia’s own territorial waters, despite the increased navigational risks posed by shallow seabeds.

“This incident clearly demonstrates that Russia continues to behave unpredictably,” Tsahkna said. “Consequently, vessels will be rerouted via an alternative path that avoids Russian waters entirely.”

The Transport Administration added that this new routing arrangement is intended to prevent further incidents and reduce exposure to sudden actions by Russian authorities. The move represents a significant shift in regional maritime practice, given the long-standing reliance on the safer Russian corridor for outbound traffic from Sillamäe.

The detention of the Green Admire follows closely on the heels of a separate maritime confrontation last week. The Estonian Navy attempted to intercept an unflagged vessel believed to be part of Russia’s shadow fleet – a network of ageing tankers used to circumvent Western sanctions on Russian oil exports. The vessel refused to halt and was later escorted by a Russian fighter jet, which entered Estonian airspace in the process.

Estonia has taken an increasingly assertive stance on maritime enforcement. In April, the shadow fleet tanker Kiwala was impounded in Estonian waters for operating without valid documentation. Tsahkna has linked Russia’s recent behaviour to these heightened enforcement measures, which he says are coordinated across the Baltic region.

“This is clearly connected to the pressure we have started applying to Russia’s shadow fleet – and I’m not just referring to Estonia, but also Finland and other Baltic states,” Tsahkna said. “Within the EU, over 300 vessels belonging to the shadow fleet have now been added to the sanctions list.”

He noted that the Gulf of Finland remains a critical artery for Russian oil exports, with between 50 and 60 percent of flows transiting through the area. Disruption to these routes, whether through direct action or coordinated scrutiny, is beginning to affect Moscow’s ability to operate freely in the region.

Despite the diplomatic implications, Tsahkna emphasised that Estonia does not currently intend to summon the Russian chargé d’affaires again. A diplomatic note was delivered last week after the airspace breach, and Estonian officials are continuing to monitor the Green Admire’s status.

“There was no use of force, and the tanker complied with instructions. We are watching closely to ensure that it is eventually allowed to continue its journey,” he said. “This is not a crisis, but it is a warning sign. Our response must be calm and deliberate, but we cannot ignore the broader picture. Russia is unpredictable, and the risks are increasing.”

According to Estonian officials, the change in maritime routing will apply immediately. While navigating through Estonian territorial waters poses more technical challenges for large vessels, Tallinn is confident in its capacity to manage the shift safely. Maritime pilots will now guide tankers through these shallows, avoiding further reliance on agreements that, in the government’s view, can no longer be trusted.

With NATO foreign ministers meeting this week and Russia’s military and commercial posture under growing scrutiny, the Baltic Sea is once again becoming a focal point for broader geopolitical tensions. Estonia’s decision to abandon the shared maritime corridor signals a recalibration of policy aimed at reducing exposure to Moscow’s unpredictability, both at sea and in the air.