&gt; the Maginot Line, which is of course a historical comedy act.

Despite it doing *exactly what it was supposed to do*. The whole point of the Maginot Line was to force the Germans to invade through Belgium.

The unexpected part was them moving through the Ardennes. French *and British* forces were prepared to hold off the Germans in the rest of Belgium, but left the Ardennes lightly guarded because they (reasonably) assumed that only an idiot would try to move major forces through the rough terrain covered in dense forests (and they were partially right - there were massive delays and gridlocks as the German units moved through the Ardennes, leaving them vulnerable. If the French bombers had attacked the *250 kilometer long traffic jam* from the Meuse to the Rhine rather than the secondary German forces at Maastricht, they almost certainly could have done *severe* damage).