Why was the West German Communist Party banned in 1956, only 11 years after it had emerged from Nazi persecution? Although politically weak, the postwar party was in fact larger than its Weimar predecessor and initially dominated works councils at the Ruhr pits and Hamburg docks, as well asthe steel giant, Krupp. Under the control of East Berlin, however, the KPD was sent off on a series of overambitious and flawed campaigns to promote national unification and prevent West German rearmament. At the same time, the party was steadily criminalized by the Anglo-American occupiers, andostracized by a heavily anti-communist society. Patrick Major has used material available only since the end of the Cold War, from both Communist archives in the former GDR as well as western intelligence, to trace the final decline and fall of the once-powerful KPD.