MOSCOW—The Kremlin and its propaganda channels have spread a flurry of theories about who was behind the nerve-agent attack on a former Russian spy in the U.K. They have one common theme: It was anyone but Russia.
The U.K. did it to frame Russia, an ex-spy chief argued. The nerve agent came from Europe, the foreign ministry said. Or it came from Uzbekistan via the U.S., suggested a senior lawmaker. Russia never produced such a chemical, some government officials maintained. Oh yes it did, a Russian scientist told a state...