No one, not even Mikhail Gorbachev, anticipated what was in store when the Soviet Union embarked in the 1980s on a radical course of long-overdue structural reform. The consequences of that momentous decision, which set in motion a transformation eventually affecting the entire postwar world order, are here chronicled from inside a previously forbidden Soviet city, Magnitogorsk. Built under Stalin and championed by him as a showcase of socialism,...