This article compares the patterns of breakdown of communist rule and the processes by which power was transferred to new ruling groups in four countries: Poland, Hungary, Czechoslovakia and the GDR. In the countries covered in this paper, two paths to systemic crisis and breakdown are identified: the path of failed reform in Hungary and Poland, and the path of intransigent resistance to reform in Czechoslovakia and the German Democratic Republic. The lesson of the Czechoslovak and East German experience was clearly that those regimes which totally rejected reform, because they saw it as incompatible with communist power, faced total and rapid collapse when confronted with the challenge of Gorbachev's perestroika and when deprived of the support of the ‘Brezhnev Doctrine’; but the experience of Poland and Hungary suggests that those regimes which embarked on reform were no more successful in preserving communist power — half-way reform turned out in many ways to be even worse than no reform at all, while radical reform, that is, reform which would bring about the intended economic results, in the end could not be achieved without sweeping away communist power. Gorbachev himself now seems to be impaled on the horns of this same dilemma in the Soviet Union.