The most recent period of opposition to the Czechoslovak regime began with the onset of what has become known as "normalisation" after the invasion by Warsaw Pact troops in August 1968. "Normalisation" is here understood as an attempt to promote an ideologically motivated and consumer-orientated legitimation of an unpopular regime under the close supervision of the USSR which retains the prerogative of supreme arbitration and interpretation but prefers to work through domestic agents.