A persuasive way of understanding the collapse of Communism in Europe and the Soviet Union is to think of nineteenth- or twentieth-century slum clearance. For in many respects the Soviet Empire was a slum of continental proportions. Beyond the grotesque architectural assertions of an alien ideology, public housing – almost all housing – consisted of anomic and primitive concrete barracks where the smells of cabbage, damp and low-grade tobacco combined. Rivers and lakes were polluted by chemicals, with the Pleisse river in East Germany alternately turning first red then yellow.