With a foreword by Seymour Lipset, Hoover Institution and George Mason University, USA examines one of the twentieth century's great historical puzzles: why did the communist-led regimes in Eastern Europe collapse so quickly and why was the process of collapse so different from country to country? This major study explains why the impetus for change in Poland and Hungary came from the regimes themselves, while in Czechoslovakia and East Germany it was mass movements which led to the downfall of the regimes.