The Maginot Line dominated French military thinking in the inter-war years. The Maginot Line was a vast fortification that spread along the French/German border but became a military liability when the Germans attacked France in the spring of 1940 using blitzkrieg – a tactic that completely emasculated the Maginot Line's purpose.
France had suffered appalling damage to both men and buildings in World War One. After Versailles in 1919, there was a clear intention on the part of the French that France should never have to suffer such a catastrophe again. After 1920, those men in both political positions and the military favoured adopting a military strategy that would simply stop any form of German invasion again.
Senior figures in the French military, such as Marshall Foch, believed that the German anger over Versailles all but guaranteed that Germany would seek revenge. The main thrust of French military policy, as a result, was to embrace the power of the defence.