Determined never again to face invasion from the East after World War 1, the French government spent a fortune building the vast line of forts called the Maginot line stretching along its Italian and German borders. In the end, the Luftwaffe simply flew over it and the German Army went around it through Belgium. Generally considered one of the great failures of military history, the term "Maginot Line" is now sometimes used as a metaphor for something that is confidently relied upon. Something similar...