MOSCOW—U.S. diplomats were leaving Russia on Thursday hours after the Kremlin failed to garner support for a joint investigation into the use of a Soviet-era nerve agent in the U.K., moves that underscore the deepening divisions between Russia and the West.
The poisoning of Sergei Skripal and his daughter Yulia has plunged ties between Russia and the West to their worst levels since the end of the Cold War. Russia, which denies it is responsible for the attack, announced the expulsion of 60 U.S. diplomats and others last week...