French society did not adjust well to the late 1800s (at least in terms of preparing for a World War early in the 20th century).

Her birth rate remained stable, while Germany's grew. France singularly failed to take advantage of the second industrial revolution, which emphasised chemical and electrical technology, and remained a nation whose wealth and population were concentrated in the countryside. This did not bode well for what was essentially and industrial war, a war embracing all of society. France did keep up militarily, fielding in 1914 an army matching that of Germany, from a far lower population base.

After 1870 the Army became a repository for revanchism, and those who prospered in the military were therefore those who emphasised the power of the attack, which was already something the French saw as peculiarly their won as it reflected a lot of what Napoleon said about will and determination.

Post 1870, French society tended to repress some elements of the gentry and aristocracy, allowing the bourgeoise elements to increase their influence. This meant the army attracted a large contingent of displaced nobles (as did the British army, for similar reasons, and also to its detriment). These men built into the French army a system of religious and family-connected powr structures, that both hampered progressive and realistic thought, held back technological integration, favoured tradition, and importantly made the army a target of criticism from progressives. This culminated in the Dreyfus case in the early 1900s, which contributed to the appointment of a war minister, Andre, who virtually purged the army.

By 1910 a patriotic revival reunited France to some extent, but the poor image of the army resulted in difficulty attracting quality recruits, and thus a lack of stock upon which to build a confident and flexible organisation.

After 1870 the French put a lot of stock in fortification, reconsidering when the Germans captured Belgian first early on with super-heavy artillery and guile. But the construction of forts did not sit well with the cult of elan that was supposed to allow the French soldier to defeat any other.

Despite all this the French fought very hard, taking the vast majority of casualties in the West in the first years of the war, with few real victories despite a long series of epic battles. World War One was a war of broken nations, only those that held back their early sacrifices surviving to 1918. The French army did not collapse in 1917, and although its offensive power was temporarily blunted, it survived in a way that the Russian army, or the German army of late 1918, did not. It would therefore be wrong to describe World War One as a debacle for France more than for Russia, Germany or even perhaps Britain.