The Franco-Prussian war of 1870-1871 united Germany through the shared joy of victory. For the French it created a very different shared experience, one that would drive French international policy for the next forty years – bitterness and resentment.
Revanchism – a political outlook that revenge on Germany and the recovery of lands lost in the war – became hugely influential in France. By 1914, many saw revenge not just as good but as necessary. Hostility toward Germany was almost a necessity for success in French politics.
In Germany too, domestic politics tended toward international war. A rising tide of liberals and left-wingers, especially in the 1912 elections, made the conservative aristocracy nervous. War was a way to remind people of the values of traditional values, whipping up a national spirit.
Primacy of Offensive Warfare
Military thinking in 1914 was radically different from where it would be four years later. Strategists believed that increasingly destructive weapons would give the advantage to offensive tactics. Those put on the defensive were likely to lose.
This meant that the militaries of the great powers all wanted to be the first into action. If war came, they needed to be the attackers, not the defenders. The best way to do that was to start the war themselves, rather than to wait for the enemy to invade.
The Schlieffen Plan
One strategy, in particular, would ensure that the war engulfed the whole continent, and that was the Schlieffen plan. The German General Staff under Count & General Alfred von Schlieffen had developed three plans for going to war – two against France and Russia, one just against France. There was no plan for just fighting the Russians.
When war came with Russia, the Germans, therefore, had two choices – attack France first, following the Schlieffen plan in an attempt to knock out the threat in the west, and guaranteeing French involvement; or abandon the plan, leaving them unprepared to attack France if that country became involved. Believing in the superiority of their planning, and the benefits of offensive strategy, the Germans went to war with France, and the stage was set for terrible destruction.