Drones sank a cargo ship and set a second one on fire off Bulgaria's coast, in what Bulgaria and the EU call the first such attack inside a NATO member's economic waters.
Multiple sea and aerial drones struck the Togo-flagged Alfa Watan and the Palau-flagged Able about 80 miles off Bulgaria on October 6, according to the Associated Press. The Alfa Watan sank. The Able caught fire, and a Bulgarian ferry evacuated its 18 crew members, flying two severely injured mariners to a hospital in Varna. At least two sailors were killed. Bulgarian President Rumen Radev called it "an unacceptable attack in Bulgaria's exclusive economic zone" and "a blatant violation of international law and maritime law."
Black Sea shipping has been a target throughout Russia's invasion of Ukraine, but those strikes have mostly stayed inside contested or Ukrainian waters. Hitting vessels inside a NATO country's economic zone moves the line closer to alliance territory, fitting a pattern Europe has already labeled hybrid warfare: cable cuts, GPS jamming, and sabotage that stop just short of open conflict.
One sunk and one burning cargo ship won't trigger NATO's mutual defense clause. But they're exactly the kind of deniable, low-grade pressure that doesn't need to.