BRUSSELS, Sept. 25 -- Late on a Tuesday evening, as the world's attention was fixed on the United Nations General Assembly in New York, the European Union quietly deleted two names from its Russia sanctions list. One unnamed European diplomat described what had made it possible. "It really sends the signal," he said, "that you can blackmail your way to delisting."

The two names were Alisher Usmanov, the Uzbek-born metals and telecoms billionaire with close ties to the Kremlin, and Mikhail Fridman, the Ukrainian-born banker who co-founded Alfa-Bank, one of Russia's largest private lenders. Both had been under EU sanctions since March 2022, weeks after Russia launched its military operation in Ukraine. Both are now off the list.

The Counc...