An investigation by Le Monde reveals how secretive Russian-linked tankers are skirting sanctions, spreading risk, and stirring fears of sabotage beneath Europe’s northern waters.
In the gray September light of Tallinn’s naval base, Estonian Navy Commander Ivo Värk surveys a row of rust-streaked tankers anchored in the Baltic Sea. They look harmless enough—hulking ships ferrying oil and gas—but to Värk they are symbols of an invisible conflict, one waged without open battles yet brimming with danger. “We don’t know everything about them,” he warns.
These vessels, known as ghost tankers, are at the center of a sprawling shadow fleet that allows Russia to bypass Western sanctions and continue selling roughly 60 percent of its oil. Hidden behind layers of shell companies and flying flags of convenience, they routinely disappear from radar by switching off their tracking systems. According to Le Monde, European intelligence agencies suspect some are being used for far more than smuggling oil—possibly for sabotaging undersea cables and even launching drones near NATO territory.
Le Monde reporters joined the Estonian navy aboard the minesweeper Ugandi to witness one of its surveillance missions. The ship, usually tasked with hunting World War II mines, now patrols the modern ghosts haunting the Baltic. Its crew scans the horizon for tankers that have gone dark, verifying ship identities through transponder signals that can easily be hacked or faked. What seems like a simple inspection can turn tense in a sea where suspicion runs deep and proof is elusive.
The rise of this phantom fleet coincides with tightening Western sanctions. The European Union’s nineteenth sanctions package, issued in September 2025, blacklisted another 118 ships, bringing the total to 560. Yet the fleet keeps expanding. Estimates from S&P Global put the number of ghost tankers at 940—about 17 percent of the world’s oil carriers, a 45 percent increase in just one year. Many of these ships are decades old, poorly maintained, and underinsured, posing mounting risks to the environment and coastal economies if disaster strikes.
For European navies, the threat has moved beyond oil leaks. Over the past year, authorities have linked a string of undersea cable breaks and mysterious drone launches to vessels tied to Russia or its commercial proxies. In one episode, a tanker suspected of lacking any legal registration was briefly detained by the French navy after drones disrupted air traffic in Copenhagen and Oslo. Similar incidents near German and Polish ports have heightened fears of hybrid warfare—a murky blend of espionage, sabotage, and deniable operations designed to test NATO’s resolve.
Estonia’s defense officials told Le Monde that the first warning signs came as early as 2023, when a Chinese ship was suspected of damaging a gas pipeline between Finland and Estonia by dragging its anchor across the seabed. Since then, a dozen cables have been cut or damaged in the region. Whether these are accidents or acts of covert aggression remains unclear. “The very essence of hybrid warfare is to act in ways the aggressor can deny,” said Andres Kasekamp, a security expert at the University of Toronto.
The tension occasionally erupts above the waves. In May 2025, when Estonian coast guards tried to inspect a Gabon-registered tanker near their territorial waters, a Russian fighter jet intervened, forcing them to retreat. Days later, Moscow seized a Greek vessel carrying Estonian oil, only to release it soon after—a tit-for-tat exchange that revealed how fragile the balance has become.
Since Finland and Sweden joined NATO in 2023 and 2024, the Baltic Sea has shifted from a neutral space into a NATO-controlled corridor—a narrow maritime bottleneck Russia cannot afford to lose. About 700,000 barrels of Russian oil pass through these waters every day. A blockade here, warned Latvian Prime Minister Evika Silina, could strangle Moscow’s energy revenues and cripple its war economy. But enforcing one could also trigger a wider confrontation, violating the freedom of navigation enshrined in international law.
According to Le Monde, Russian state media now frames the Baltic as a potential “theater of military operations,” and several of its tankers have been spotted under naval escort. In response, NATO has launched Operation Baltic Sentry, deploying frigates, patrol aircraft, and maritime drones to protect underwater cables and pipelines. Estonia, with a population of just 1.5 million, is expanding its tiny navy, though its only submarine remains a museum relic—a reminder of how precarious its maritime defenses once were.
During a European summit in Copenhagen, French President Emmanuel Macron called for tougher European action against the ghost fleet. Days later, Denmark announced stricter environmental inspections on tankers waiting off Skagen. Yet for commanders like Ivo Värk, the danger persists just beyond the horizon—rusted tankers that may carry more than oil, drifting silently through the cold waters of a sea now central to Europe’s new shadow war.
