Flag-State Jurisdiction Explained: Russia’s Shadow Fleet Dilemma
Throughout 2026, European coastal states have pushed sanctions enforcement to a new frontier: the sea. The UK, France, Belgium, and Sweden have been boarding and seizing oil tankers that help Moscow reap oil revenues. Over the summer, the bloc stepped in with EU naval missions intercepting shadow fleet tankers further from European coastlines.
Moscow has relied on the fleet of over 1,000 old, uninsured tankers registered in third countries to discreetly sell oil above the price cap and avoid sanctions imposed over Russia‘s war in Ukraine. But as EU diplomatic efforts and sanctions enforcement have strained access to convenient ship registries, Moscow is seeking to neutralize the most effective legal hook in the EU’s toolkit: false flags.
International maritime law grants a flag-state — a country where the ship is registered and whose national flag it is flying — exclusive authority over the ship. In practice, this means that no other country can board, inspect, detain, or divert the ship’s course other than the flag-state. Some countries limit access to their own nationals, others have open registries.
The Law of the Sea also states that there must be a link between the ship and the flag, but in reality, this requirement is often flouted. “We have ships that have never visited the country they are flagged in, nor have their owners,” Henrik Ringbom, Environmental Law and the Law of the Sea at the Åbo Akademi University in Finland, said. “This has been a common practice for business purposes since the 1950s, what is called the flag of convenience, but it has not been considered illegal despite this requirement.”
How Can a Ship Lose Nationality?
A common scenario for a ship losing nationality is when the registry expels the ship. EU diplomats persuade flag-state governments to remove sanctioned tankers, limiting the number of flags-of-convenience available to Moscow.
By deregistering sanctioned ships, states avoid secondary sanctions. As of August 2026, the EU has sanctioned over 670 ships linked to Russian oil trade; some countries still provide flags to tankers on EU and UK sanctions lists, but not those sanctioned by the U.S.
For example, Cameroon deregistered 36 shadow fleet vessels, including oil tanker Smyrtos in early June. On June 14, the British Navy seized Smyrtos in the English Channel and arrested the Indian-national captain for allegedly breaching sanctions. The tanker is still at anchor off the south coast of England.
Flag-Hopping and False Flags: Russia’s Shadow Fleet Tactics
Governments can also appeal to environmental and safety concerns due to the age and poor maintenance of the shadow fleet. Countries that are stricter with compliance will also remove ships if they no longer meet the national standards; the flags of convenience states, however, are notorious for loose regulations and poor enforcement.
Often, ships that help duck sanctions would switch registries and names at their own initiative to evade identification, a deceptive practice known as flag-hopping. In other cases, ships are not registered at all and fly a false flag. In 2025, shadow fleet tankers commonly displayed the flag of
Original Article: Russia’s shadow fleet flag dilemma explained — Theparliamentmagazine