Where is the historical site of World War II, and what were the causes of its escalation? After Stefan Scheil described the trend of increasing non-European influences in intra-European conflicts as a phenomenon of modern times in "Logik der Mächte" and provided a detailed account of the outbreak of war in 1939, he now turns to the history of diplomacy between the autumn of 1939 and the summer of 1940. In various retrospectives, the author addresses further aspects of the background, such as the details of the alliance treaties that were concluded in 1939. A particular focus of the presentation is on the German-Polish relationship and Polish politics. Scheil attributes the escalation of intra-European conflicts leading up to World War II to the contradictions among the five major nation-states, which he includes alongside England, France, and Italy.