‘Coercion and participation’ shows how the terrorist proclivities of the Soviet state were modulated by an ideology of grass-roots social mobilization and collectivism. The ‘necessity’ of terror during the revolution created the mindset and language for subsequent terror campaigns. There was a formidable institution of violence that offered scapegoats for any problem. Terror was a continuation of the revolutionary suspicion of the early Bolsheviks. The ‘Soviet’ base taken over by the Bolsheviks was a democratic one, and the notion of popular participation remained important. Post-war stability saw flagship projects replace terror as a means of popular participation. In the Brezhnev era, participation waned, before Perestroika improved popular engagement again.