An oasis of authorized criticism in the 1960s and the 1970s, and a privileged public arena for ‘extreme non-conformist’ intellectuals in the same period, ecology was also the matrix for the national movements which precipitated the end of the decaying party-state at the end of the 1980s and which had been in gestation since the late 1960s. Ideal metaphor for the fall of a system emblematized by the catastrophe at Chernobyl (April 1986), the ecological crisis - the crisis in the relationship between nature and urban space - made it possible to understand the full extent of the post-war upheavals that had taken place at the heart of Soviet society. The rapid, huge-scale industrialization and urbanization of the country had produced a new educated middle class of ‘specialists’ (technicians, engineers, applied research managers, economists and administrators, and so on), which in the early 1960s constituted the hard core of the first generation of Soviets to be a majority of urban-dwellers. If it was not embodied, as in Western countries, in political movements or parties, the ecological cause was no less institutionalized. The horticultural societies (tovariscestva) on the edge of towns (ogorodniki), the ‘nature protection brigades’ which organized reafforestation campaigns (DOP), the Society for the Protection of Nature (VOOP), or local historical and ethnographical societies (kraevedenie) had a considerable number of supporters. It allowed the expression of a very extensive range of individual and collective sentiments, and of reactions both rejecting and adapting to a radically new natural, social and cultural environment - that of the town and a larger community. For a disorientated society, it was a question of re-appropriating its immediate, daily environment, of attempting to impose, individually or collectively, meaning on its existence and its social trajectory. Ecological sentiment was thus intimately bound up with the emergence of an ‘urban civilization’ in the Soviet Union under Brezhnev.