We are generally quite well informed about Germany’s attack on Luxembourg, Belgium and France in early August. For the purposes of British heritage commemorations it serves as the act that triggered Europe’s plunge into war, and its adherence to the Schlieffen Plan – a precisely timetabled blueprint for a swift, knockout punch against France that dated back to the 1890s – is seen as evidence of Germany’s prime responsibility for the catastrophe. The story has less to say about French aggression. France had been preparing an attack on Germany since ceding territory to a victorious Prussia in 1871. It possessed its own plan to deliver a knockout blow, and it could hardly wait to get an invasion started.
Plan 17, the French strategic blueprint for war, was the brainchild of Ferdinand Foch, the general destined to end the war as commander-in-chief of allied forces on the Western Front. Adopted in 1913 by the then c-in-c of French forces, Joffre, it was more flexible (and a lot less precise) than the Schlieffen Plan, and reflected the French Army’s dogmatic commitment to offensive warfare as the key to military success. A radical departure from previous plans, which had been focused on defence of the Belgian frontier in response to a German attack, it called for French forces to retake Alsace and Lorraine, the eastern provinces lost in 1871, and then to push further east into Germany through the Ardennes forests.
With hindsight, the greatest weakness of Plan 17 was that it was based on a giant miscalculation. French leaders had spent a decade trying and failing to get a British commitment to defending France if Germany attacked. Joffre and most of his senior commanders refused to believe that Germany would force Britain off the fence by invading Belgium, and steadfastly ignored the possibility that Berlin might interpret Britain’s deeply opaque diplomatic fudging as licence to get away with just that.
Plan 17 did allow for a turn north to protect Belgium and Luxembourg, but this was an afterthought and treated as such, so that even an ominous build-up of German forces around the Belgian frontier in the summer of 1914 was interpreted as good news because it weakened defences in Alsace and Lorraine. With or without hindsight, the fact that well-trained German reserve forces could be brought up to plug any gaps in Alsace and Lorraine might have worried French commanders, but they weren’t the first or last powerful men to see the world as they wanted it to be.
After a delay to be sure the British saw France as victim rather than aggressor, Plan 17 swept into action with a preliminary attack into Alsace on 7 August, its planners confident that an invasion carried out with sufficient élan (by which they meant attack-minded verve and flair) would carry all before it.
It didn’t. German forces withdrew from Alsace to await reinforcements, and although France erupted with joy as the major town of Mulhouse was ‘liberated’ without a fight (and with most of its German-speaking citizens notably absent), a German counter-attack arrived two days later and drove the French slowly back. A change of commander and belated reinforcement did enable the French to regain Mulhouse later in the month, but by that time part two of Plan 17, a full-scale attack into Lorraine, had run into serious trouble.
It was the kind of trouble soon to become familiar on the Western Front. Two French armies advanced into Lorraine from the north on 14 August and attacked the towns of Sarrebourg and Morhange, coming up against the German Sixth Army, a largely Bavarian force deployed along a line protecting the towns. French infantry charges were easy meat for entrenched troops armed with machine guns and artillery, and attack-minded French forces had no trenches of their own in place when German commander Crown Prince Rupprecht (the heir to the Bavarian throne) launched a counterattack on 20 August.
Within two days French forces had been driven back to a line of fortified bases on high ground east of Nancy. Two days after that, on 24 August, the invasion of Germany was officially called off, by which time French, British and Belgian forces were manifestly on the defensive all along the northwestern frontiers of France. On the same day Rupprecht, having persuaded his High Command to divert strength from the drive on Paris further north, launched a major offensive against the French line, only for roles to be reversed as three days of German assaults failed against well-prepared trenches. The sector then subsided into armed stalemate for most of the next four years.
Heritage has pretty much forgotten about the French invasion of 1914, and that means its inadvertent contribution to the defeat of Germany’s invasion is also left out of the story. If the French attack on Lorraine hadn’t failed badly enough to give Prince Rupprecht visions of glory and massive reinforcement to carry them out, the German thrust further north towards Paris would have been considerably, perhaps decisively stronger. That’s history for you – everything connected up in ways heritage, with its perceived need for simple straight lines, finds inconvenient.