THE OPINION THAT the whole German nation is responsible for the outbreak of World War II was a subject of many discussions over post-war order in Europe and the future of Germany. But it became particularly important for the Czech political thought. The statement that the whole German population is responsible for the crimes of war, became the starting point for the discussion about the future of the Czech Republic and the solution to the problem of German minority, which had been a problem for Czechs for 20 years, and which caused the decline of the young state – the Czechoslovak Republic. Although not all Sudeten German supported Hitler and many of them even became the Nazi persecution victims, considering the German population in general as the one to be guilty for causing and consequences of the war, dominated in thinking about the future of the country. The idea of collective responsibility, which was against the international law, was not the official slogan of the Czechoslovakian authorities and other active political groups in the country and those in exile, and the documents which were supposed to regulate the reconstruction of life after the war, including settling up the Nazi crimes, determined the groups which were to receive punishment and the ones which could avoid being punished. But in practice the distinction was not taken into account, which was particularly noticeable in case of forced displacements of German population from Czechoslovakia, which included almost all German, irrespective of their attitude to the Nazi regime. The principle of the collective responsibility often appeared in the statements of prominent politicians of all Czech parties. The thesis of the collective guilt served not only as a tool for settling up the war crimes, but mainly to solve the problem of national minorities once and for all, which influenced significantly the domestic situation and the future of the First Republic. According to such an attitude, the thesis was not a way to reckon with the past, but the element of the construction of the Czechoslovakian future. It is obvious that for the country’s authorities and its citizens the safety was more important than law standards and international agreements.