World War I casualties
The total number of military and civilian casualties in World War I were about 40 million: estimates range from 15 to 19 million deaths and about 23 million wounded military personnel, ranking it among the deadliest conflicts in human history.
Francophobia
The prime ministers of France between the World Wars were generally frightened about German intentions, as France sustained more casualties in the First World War than any other Western country, approximately 1.4 million military and 1.6 million total casualties. Accordingly, French policies towards Germany in general, more specifically the Nazis, were more aggressive than that of other Western nations. Relations were very poor at the time, and French leaders were also acutely aware that the population of Germany (64 million) exceeded that of France by a considerable margin (40 million), a major strategic vulnerability.