Ukraine said Thursday its long-range drones had struck a major offshore oil platform in the Caspian Sea this week, in a previously undisclosed mission that signals a new expansion of its target list in a mounting campaign to cut off the Russian energy revenues funding its war.

Ukraine’s deep strike campaign against Russian energy facilities began in earnest in early 2024, but since the beginning of August, Kyiv has escalated this effort, doubling down on what Ukraine’s sanctions commissioner Vladyslav Vlasiuk calls “long-range sanctions” targeting Russia’s biggest financial lifeline. Ukraine is now hitting an increasingly broad range of targets including not just refineries but oil and gas export infrastructure, pipelines, tankers, and now offshore drilling infrastructure.

It comes at a critical juncture in the war. Recent US-led peace efforts only appear to have hardened Russia’s maximalist demands, and Moscow’s forces are creeping forward in several areas of the front line. That, along with a global oil supply glut cushioning the market against potential price rises, means Ukraine’s Western allies have grown increasingly supportive of this campaign.

Ukrainian strikes on Russian oil infrastructure

The strikes have hit critical oil facilities such as refineries, depots, export terminals and pipelines. Ukraine’s drones and missiles have extended deep into Russia, the farthest of which reached an oil refinery in Omsk, Siberia, over 2,500 km (1,560 miles) away from the Ukraine-Russia border.

Ukrainian strikes on Russian oil infrastructure, since February 2022

Dubey’s research shows that repeated strikes on Russian refineries like Saratov have knocked a significant amount of capacity offline and are “slowing the pace of every repair.” He also assesses that since August, Kyiv has been trying to maximize the impact of its refinery strikes, by targeting not just “the visible parts of the refinery but the important clogs in the refining system that produce the final fuels.”