This essay contains reflections on the role of war in European history and on contemporary Europeans’ awareness of the wars currently underway. In the historical part of the text, the author refers to the classic justification of the creation of a state as an alternative to war. The author recalls the conflicts and destruction in Europe to the end of the nineteenth century – an era in which war theoreticians and national leaders treated war as an acceptable tool for obtaining political aims. Then the author presents the world wars of the twentieth century as a threat to the existence of Europe and the process of building – in this century and with the large participation of Europeans – an international system to prevent conflicts. In the pa...