Marshal Edmond Leboeuf, France's war minister in 1870, would himself have winced at the task set him by Gramont and Ollivier. In 1870, the fully mobilized Prussian army would number more than a million men. Against this armed horde, the French would be lucky to amass 400,000 troops. The reason for the disparity was the differing mode of recruitment in Prussia and France. Whereas the Prussians relied on universal conscription – raking every able-bodied twenty-year-old into the army for three years, then releasing him into the reserves for four additional years and the Landwehr or national guard for five more – the French preferred long-service, professional soldiering, employing no reserves and recruiting fewer men but keeping them longer with a seven year hitch and bonuses for reenlistment. The two systems could not have been more different. Fifty percent of the French army in 1870 had served seven to twenty-one years on active duty.

The Prussians were greenhorns by comparison. Indeed with its short, compulsory service, the Prussian army was essentially a training school for the reserves, ratcheting a relatively small peacetime strength of 300,000 up to 1.2 million with the call-up of 400,000 reservists and 500,000 Landwehr. The chief defect of the Prussian system was its relative amateurism; the officers and NCOs were the only career soldiers in the army, which made it difficult to build an expert reserve and train new formations.