25 years ago: The (almost) non-violent end of the totalitarian systems in Central Europe

In 1989/90 the totalitarian political systems in Middle Europe changed almost simultaneously, but in different ways. In Hungary, the ruling communist party (Hungarian Socialist Workers' Party) transformed the system. In Poland, the communist Polish United Workers' Party negotiate transformation with the Catholic opposition (especially represented by the trade union "Solidarity"). In the GDR, the freedom movement changed into a movement for the unity of the two German states. In Czechoslovakia the political system imploded within a few days, the people had triumphed. All this was done by an unexpected European revolutionary movement, favored by the changed foreign policy doctrine of the Soviet Union during the Gorbachev era.