The pastoral calm of the Warndt Forest in the Rhine Valley had been broken on September 7th, 1939; the soothing sounds of nature quickly replaced with the creak of tank tracks, the roar of trucks, and the stomping of men on the march. Only three days earlier, Germany’s western frontier had become a potential battlefield as Britain and France had declared war over Berlin’s invasion of Poland. For the second time in a generation, the Franco-German border would be a scene of intense conflict.
But the soldiers on the move were not members of the Wehrmacht. Most of Germany’s border towns had been cleared of both soldiers and civilians with the coming of a Second World War. These men were members of the French Second Army Group, part of 11 divisions and the opening wave of a planned 44 division invasion of Germany that would pull enemy forces away from a beleaguered Poland and dive deep into Germany’s industrial core. In all, the Allies had an estimated 110 divisions they could turn against Germany while the Nazis had, at most, 22 undermanned divisions to repel any such attack.
A week into the Second War World, France was in German territory. The outcome of the conflict rested on Paris and London’s willingness to stay on the offensive.

A French soldier inspects a German poster in the Saarland during the French invasion of Germany
In some respects, September 7th, 1939 was a date that France had planned on for 20 years.
Since the end of the Great War, military and political leaders in both France and Britain had sought to emulate an “Entente-lite” coalition to box in Germany in the event of a future conflict. While an alliance of new, smaller nations like Czechoslovakia and Poland could hardly match the industrial output and manpower of a Tsarist-era Russia, any tangible military threat in the east would ensure that if another conflict began, Germany would again find itself gored on the horns of a two-front war. To cement such a position, Czechoslovakia, Romania and Yugoslavia would form the “Little Entente” with French oversight, while Paris signed a direct defensive alliance with Poland in 1921. The French-Polish Treaty assumed that France would take offensive action against Germany within three days of starting mobilization while launching a full-scale assault within 15 days, presumably while Poland would fight any rearguard action to buy time. Continue reading