This is the first book in the series "Was there an alternative to Stalinism?" on the history of the political struggle inside the Bolshevik party. It studies the causes of the Stalin terror in 1934-1936. Based on materials which only recently became available, the author attempts to prove that the political terror in the 1930’s was Stalin’s response to existing Bolshevik opposition. The book includes comprehensive bibliographical references (pp. 357-375) and a name index.