In the years leading up to World War I, French military thinkers had wavered back and forth over the best strategy and tactics to employ in the forthcoming struggle with Germany. Most of them were not pushing for conflct, but there was a general feeling that war was inevitable.
In 1870-71 France had lost a war to a united Germany in what is generally referred to as the Franco-Prussian War. During that war the French army, consisting of professional, long-serving soldiers, had been overwhelmed by a virtual nation-in- arms. Prussia and many of the other German states had universal military conscription, and the French were seriously outnumbered in all the critical early battles.
After 1871 France also adopted universal conscription. There was a problem by 1914, however, in that Germany’s surging population outnumbered France’s by more than 50%. To compensate for this increasing imbalance, in 1913 France changed the term of recruitment to three rather than two years. This meant that the standing armies were approximately equal in size, but Germany had a much larger reserve of trained soldiers. Military doctrine at that time assumed that the reserves would be shuttled into combat as replacements for regulars, but the German high command, in an all-out effort to overwhelm the French, decided to place reserve division in line with the regular divisions, thus giving the massive German right wing an enormous numerical advantage as it swept through Belgium into northern France in August 1914.
As for tactics, the French had adopted a belief in “offensive à outrance” (offensive to the extreme) theories. Essentially, this was a conviction that the will to win combined with a vigorous charge into the face of the enemy would achieve victory. The enemy’s own capabilities and dispositions were of secondary consideration. In the early days of fighting, German numerical superiority and advantages in heavy artillery and machine guns, when combined with these unrealistic French tactics, produced almost unbelievable casualties. On one day alone, August 22, 1914, 27,000 French soldiers died in battle and another 80,000 or more were wounded. This was more than 100,000 casualties on one side in a single day of battle. German casualties were probably at least half those of the French. Similar bloodletting went on up and down the lines of warfare from mid-August through the first weeks of September.
Nothing is more instructive that the actual shock of combat. Nevertheless, is somewhat amazing that the French army was able to recover from its losses, learn from its mistakes, and throw the Germans back at the great Battle of the Marne on September 6 – 10, 1914.
Casualties continued to be high on both sides throughout the course of the war, but no single day of combat ever quite matched the slaughter experienced on that calamitous day in August 1914.