Inside the sea war to contain ‘dark fleet’ vessels — and what the US seizure signals to Russia

U.S. seizure of Russian tanker Bella I marks rare escalation in sanctions enforcement against Moscow's dark fleet operations, experts say.

"This is unique," said Brent Sadler, senior research fellow at the Washington conservative Heritage Foundation think tank. 

The U.S. rarely boards foreign-flagged vessels on the high seas unless the ship’s nationality is in doubt, which he said was the case here due to rapid reflagging and a pattern of sanctions violations.