What is the 'shadow fleet' and why does everyone keep mentioning it?

The shadow fleet is a term for the hundreds of ageing tankers Russia has assembled to keep exporting oil despite Western sanctions. The G7 price cap was supposed to limit what Russia earns per barrel by denying Western insurance and shipping to any cargo sold above the cap. Russia's answer was to buy up old ships, register them under flags of convenience, insure them through opaque arrangements, and sail them with transponders switched off.

Why it matters: the fleet is how Russia funds the war. Estimates vary, but it moves a majority of Russian seaborne crude. Cutting it off would hurt Moscow far more than most other sanctions.

The problems are practical. These ships are old, badly maintained, and often uninsured against spills, so an accident in the Baltic or the Danish straits could be an environmental disaster. They are also hard to stop legally in international waters. European countries have started boarding and detaining some, and Ukraine has taken to hitting them with drones, which is where the Arctic Metagaz story fits in.

India comes up in this conversation because Indian refiners have been among the biggest buyers of discounted Russian crude, much of it delivered by exactly these ships. That is the leverage behind the US threat of sanctions on Russian oil buyers.