Salty, tidal-looking, and bigger than Germany, the Caspian fails the classic sea test on a technicality. Five countries spent 20 years fighting over what to call it instead.

War risk premiums for Hormuz tankers have jumped 40-fold since February, so Washington is now backstopping up to $40 billion in oil and LNG shipping insurance itself.

Crude has round-tripped much of its wartime spike as Gulf shipping resumes, but the weekend's strikes show how fragile the relief is.

Brent crude fell to $75.79 on Wednesday, its lowest since the eve of the Iran war, as the Strait of Hormuz reopened and Iranian barrels flowed back to market.

A confirmed truce between Washington and Tehran sent Asia-Pacific shares to records and knocked oil lower, handing central banks a sliver of relief days before the Fed decides on rates.