A revolution did take place behind the Republican lines. It was reversed by the Stalinists and their allies. Through the Popular Front, the puppet government of Doctor Negrín permitted the work of Russian secret services, murders and torture that demoralised workers and peasants. In the economy, the development of collectivised land and industry was sabotaged through the blockade enforced by another Popular Front government, in France. This book presents a spectrum of contemporary left viewpoints. These are introduced and annotated in detail. An essay by Andy Durgan surveys the development of Trotskyism and of the POUM.