The Moscow correspondent of The Guardian reports on his tour of duty there over the past three years. While there is a certain sameness to books by Western journalists on the Soviet Union, Walker's has the advantage of being up to date and sharp in seeing the realities behind the facade. He is convinced that Western, especially American, understanding of Soviet society is woefully inadequate-although he excepts American diplomats and journalists in Moscow from this judgment. He takes Gorbachev very seriously as representing an irreversible social revolution that has taken place since Stalin's day-including the rise of a new class with its own imperatives-a revolution that makes Gorbachev's push for reform not only possible but inevitable. A good book to have at hand as the Gorbachev era unfolds.