Historians often date the end of the real, as opposed to the chronological, 19th century at 1914, the year Europe exploded into World War I. This was the first total war, in which governments mobilized the full resources of the state and society to achieve victory. World War I led to the success of Bolshevism in Russia and indirectly to the rise of fascism. In France, however, these developments had less immediate impact. To be sure, France suffered from the heavy economic and human costs of the war, which left deep scars on the participants and introduced a level of violence that would have repercussions later.

Even so, the continuities in France between 1914 and 1930 were more striking than the changes. After a period of adjustment, the economy rebounded, and the government gradually solved its fiscal problems. Although the war lowered birthrates, these rates had been falling before the war. Diplomatically, France regained territory it had controlled before 1871, but otherwise the war settled little. In the 1920s French diplomats contended with more or less the same nationalist rivalries that had fueled World War I.