French casualties in WW IThere simply weren’t enough young, marriage-age men left in France after WW I to regenerate the population. Mark Steyn wrote about this in “America, Alone.” The ennui resulting from the two great wars resulted in Western Europe fertility rate in the late 20th century falling below replacement, ushering in the moslem hordes.
by Henry Copeland
September 22, 2003World War I cost France 1,357,800 dead, 4,266,000 wounded (of whom 1.5 million were permanently maimed) and 537,000 made prisoner or missing — exactly 73% of the 8,410,000 men mobilized, according to William Shirer in The Collapse of the Third Republic. Some context: France had 40 million citizens at the start of the war; six in ten men between the ages of eighteen and twenty-eight died or were permanently maimed.
Also, the French Army mutinied in 1917 (the Brits and Yanks basically saved their skittles) and hadn’t truly recovered by 1940.