Maginot line is a miracle in the military field, but why did it become a joke?

Maginot line was once a miracle in the military field, but why did it become a joke in the end? Maginot line was built by France after World War I to prevent German invasion. It was built in the northeast border area of France. 1928 started construction and 1940 was completed. The total cost of the project is 5 billion francs. The main body of the defense line is reinforced concrete and very strong. There are all kinds of cannons, trenches, forts, kitchens, power stations, hospitals, factories and so on. And the channels extend in all directions, and there are tram passages in the larger fortifications. From the strategic point of view of the whole defense line, it is a precedent. Maginot line is on the defensive, and there are hundreds of multi-faceted castles and forts in the whole defense line. There is trench protection in front of each bunker. At the same time, the fortress is equipped with hundreds of guns, large and small, and the fire suppression cannot be underestimated. Secondly, a barracks is preset 20 meters underground in each fortress to accommodate the army. Such a well-designed defense line is second to none in the history of military architecture. Why did it finally become a joke? One by one, listen to me.

During the First World War, the Germans swept across Europe, and the French army, which claimed to be the strongest force in the European continent at that time, was also beaten out of the water by the Germans. After World War I, out of concern for the Germans? Fear? In addition, in order to protect French industry, the idea of establishing a defense line was put forward. 1930, the construction of maginot line started after the appropriation of Congress. Because of the complicated design, the whole defense line is extremely expensive. In the French plan, this line of defense was reserved only to resist the German onslaught. However, the facts can't keep up with the changes. In the French plan, the Germans will attack from central Belgium, so in the whole plan, maginot line is the whole defense focus, and in the Ardennes area on the border between France and Belgium, almost no troops are deployed. As soon as the war started, the Germans stormed the Netherlands and induced the British and French allied forces to support the Netherlands. After the British and French allied forces shifted their center of gravity, the Germans attacked the Ardennes, bypassed maginot line carefully constructed by France, and besieged the British and French allied forces in Dunkirk. Without firing a shot, the defense line fell on the altar and became the laughing stock of everyone.

The wrong military thinking of the French army is in sharp contrast to the flexible tactical changes of the German army, and it also makes the carefully constructed defense line a decoration. War is not blind defense. Only by improvising can we always prevail.