Ukraine claims it has the legal right to attack Russia's "shadow fleet" tankers, which are critical for circumventing international sanctions and funding the war effort. Kyiv justifies these actions by arguing that these vessels function as legitimate military objectives. This stance is supported by the "Law of Naval Warfare" (LNW), which historically allowed belligerents to target economic activities sustaining an enemy's war capabilities anywhere outside neutral waters.
The "shadow fleet" consists of aging oil tankers operating under flags of convenience with opaque ownership structures, often lacking proper insurance and safety oversight. While Ukraine views these vessels as direct contributors to Russia's military actions, some legal scholars and international bodies, like the San Remo Manual, generally distinguish between direct military contributions and broader "war-sustaining" economic activities. The latter are typically not considered legitimate military objectives under Article 52(2) of Additional Protocol I, which requires a direct, not remote, connection to military action.
Despite the legal ambiguities, Ukraine has already targeted several third-state flagged vessels, including the Kairos and Virat, and the Dashan. These attacks, often carried out by drones, are seen as part of a broader campaign to undermine Russia's crucial oil export revenue. The lack of clear state protest or criticism regarding Ukraine's targeting of oil infrastructure has been interpreted by some, including legal expert Wolff Heintschel von Heinegg, as tacit endorsement for a broader interpretation of military objectives to include war-sustaining assets.
Ukraine's actions create a complex legal gray area between maritime law, war necessity, and international diplomacy. While the UN Charter's principle of self-defense might justify attacks if the vessels demonstrably contribute to Russia's war effort, the opaque nature of the shadow fleet complicates definitive legal attribution. This situation poses a growing dilemma for global shipping, impacting insurance costs and expanding war risk zones, as hybrid warfare blurs the lines in the maritime domain.
