What were the long-term reasons that made France enter World War 1?

Answer 1

There was only one long-term reason for France's hostility to Germany in 1914 - the fact that after the Franco-Prussian (in effect Franco-German) War of 1870-71 Germany had annexed Alsace and Lorraine.

German claims to these areas were extremely weak. Although Alsace was German-speaking, its inhabitants saw themselves as French, not as Germans. In the case of Lorraine, the population didn't even speak German. In addition, France had to pay reparations. The real reason for all this had nothing to do with the language(s) spoken in the area, but was an attempt by Germany to weaken France permanently.

In his retirement in the 1890s, Bismarck described the annexation of Alsace-Lorrains as by far his worst blunder, as it turned France into a permanent enemy of Germany, seeking to regain the lost provinces.

Historians in both France and Germany then served their respective nations by projecting the conflict back to the 9th century and the break-up of Charlemagne's empire and mythologizing it as long-standing 'hereditary enmity'.

The French desire for revenge was so great that in 1892 France formed an alliance with autocratic, Tsarist Russia. They were very strange bedfellows - a republic and a very oppressive absolute monarchy.

Joncey

-Germany attacked France because France tired really hard for over 200 years to keep Germany ununified. If France kept them ununified then France would keep there status as a powerful country in Europe.