Overview

• A joint SourceMaterial–POLITICO investigation found at least five Russian-linked tankers left oil slicks in European waters over the past year, with two already under U.K. sanctions.
• Denmark announced intensified environmental inspections of older oil tankers transiting its Baltic Sea straits, citing heightened risks and intelligence reports, referenced by President Volodymyr Zelensky, that shadow-fleet ships may be used for drone operations.
• Despite EU and U.K. blacklists covering roughly 444 and 450 vessels respectively, opaque ownership and underinsurance persist across an estimated 1,300-ship fleet, allowing continued voyages through European waters.
• National enforcement has been uneven, with Estonia detaining a suspected shadow-fleet tanker in April and French forces boarding another last week, as President Emmanuel Macron signaled upcoming joint actions with NATO to hinder suspicious ships.
• EU policymakers and analysts urge targeting the broader value chain, including refineries, service providers and flag registries, as experts warn a major spill could cost up to €1.4 billion to clean up.