In the years following its defeat in the Franco-Prussian War, France entered a new era in its military history and its strategic planning. France had gone to war in 1870 with little forethought and preparation, and its swift defeat came not only from the excellence of the Prussian military but also from its own confusion and mistakes on the battlefield. In 1874, a committee in the National Assembly charged with proposing a new law on the administration of the army stated, “[W]e cannot stamp our foot upon the ground and expect invincible armies to emerge.…[W]e must prepare and organize in advance the armed forces of the nation if we want them, at the time of danger, to be ready for prompt and energetic action.” Over the next forty years the French attempted to think through the military challenges they could face and slowly but surely adapted to the contingencies and threats they perceived. By August 1914, they had thoroughly reformed their army, but the opening battles of World War I revealed many shortcomings. While planning and preparation had helped, errors in strategy, weapons acquisition, and doctrine cost them dearly. In the end, the ability to improvise enabled the French to win the Battle of the Marne, but the failure to anticipate and prepare for the long, deadly war that ensued cost them even more.

Perceived Threats and National Goals

In the wake of the 1871 debacle, France did not have to search far for threats.