The article analyses the work “History of the German Army” by the French historian and public person Jacques Benoist-Méchin (1901-1983). Notorious for his active collaborationism during the Second World War, he was sentenced to death afterwards, but was pardoned by the French President Vincent Auriol. Therefore, that period of his life obscured his activity during the interwar period, which, however, presents a considerable interest. Being an active supporter of the Franco-German reconciliation and cooperation at that time, in his work about the German army, Benoist-Méchin analyses the challenges, which it confronted at the end of the First World War and during the Weimar Republic, and the role of the National Socialism in its “rebirth”. Important for the formation of Benoist-Méchin's views were his personal observations of events taking place in Germany in the 1920s, and the fact that, due to his nationality, he perceived German history through the prism of French realities. Thus, the position presented by him in ‘History of the German Army’ helps to understand the reasons that prompted him to collaborate during the Second World War. This, in turn, presents new opportunities for understanding the intellectual foundations laid in the interwar period, which not only became the basis for a tolerant attitude towards National Socialism, but also contributed to the fact that European social and political circles saw its true nature too late.