Maginot Line

Maginot Line
Maginot Line

There was never unanimous consensus among military men about the lessons of World War I. When the adversaries of 1914–18 fought again in 1940, the Germans interpreted their experience as one that taught the need for a rapid and forceful offense.

Interpreting that same conflict quite differently, France planned to fight almost purely defensively in the first stages. It would then attack the Germans, who they believed would have worn themselves out assaulting the centerpiece of French strategy, the Maginot line.

Planned in the 1920s and essentially completed by 1935, the Maginot line (named after a French minister of war) was a network of fortifications on the border between Germany, Luxembourg, and Italy. The line was designed and built to serve several purposes.


First, the Maginot line would protect French industry in the Alsace-Lorraine region. Second, a strong defensive line would help the French make the most of their available forces while mobilizing their remaining reserves.

Finally, it was envisioned that the Germans would go directly for the line, allowing the French to hold them off and inflict heavy casualties. The relatively fresh French would then launch an assault of their own and defeat the Germans on their own territory.

The Maginot line was not an uninterrupted line like the trench system of World War I. Instead, it was a network of steel and concrete fortifications facing the Germans to the east and the Italians to the southeast. Each fort (commonly designated as an ouvrage, or work) was an independent structure; in all there were over 100 of these with additional minor fortifications.

maginot line fort diagram
maginot line fort diagram

Using guns in a variety of calibers, each fort was within the range of another so they not only could fire on assaulting troops but could also cover other forts in the immediate area. To add further support, there were permanent garrisons of "interval troops," infantry units that would provide support in the areas between forts.

The forts were among the most advanced technical structures of the day. Each had large storage areas for ammunition, facilities for food supplies, command centers, fire control centers, miles of tunnels, small railroads, air-conditioning, electrical power plants, and water supplies. In addition, the guns were mounted in turrets that used a series of complex, highly advanced mechanical devices to change elevation or direction.

The line was strong, it reflected state-of-the-art technologies for the 1930s, and it even made a high degree of military sense. There were, however, drawbacks. Perhaps the most significant of these was that the line did not go all the way to the North Sea.

Maginot line turrets
Maginot line turrets

France did not extend the line for several reasons: the expense, the unsuitability of the terrain, and the appearance that France was abandoning Belgium. In fact, the French believed that while the Maginot line was holding, the newly mobilized French forces would join with the Belgians to contain the German advance.

Together, probably with British assistance, they would then advance through Belgium and eventually invade Germany. At the same time, the French made an assumption that the very northern end of the Maginot line, which stopped near the Ardennes, would be safe, as the Germans would never launch a major offensive through the rough terrain there.

Although war was declared in September 1939, there was no significant action by either side on the western front until May 1940. This period, known as the phony war, allowed the British and the French to mobilize and bring their troops to hold positions without interference by the Germans.

German invasion
German invasion

On the morning of May 10, over 100 German divisions attacked the French, British, Belgians, and Dutch. The main German attack went through the Ardennes forests and mountains in Luxembourg, south of Liege, exactly where the French had assumed it would never take place.

Thus, the German tanks and motorized forces went around the extreme left flank of the Maginot line and straight into France. They bypassed the line and did not attack it directly until after the British evacuation from Dunkirk and the surrender of the French government. The Maginot line forts surrendered only when their mobile interval troops had retreated and they were completely surrounded.

The Germans occupied the Maginot forts but did not maintain them. They used them only briefly when the United States attacked some nearby French cities in 1944 and 1945. After the war the French army reoccupied them and used them. In the years of the cold war, they provided headquarters and communications centers that would have provided significant protection in the case of a nuclear war.

In the years between the world wars, the French were not alone in seeing the usefulness of fortifications. Although they would rely upon a highly mobile and powerful offensive, the Germans maintained two lines, one facing Poland (the East Wall) and one facing France (the West Wall, better known as the Siegfried line, which would be used in 1944 against the United States).

In addition, Czechoslovakia constructed a line of defenses built with French assistance. Finally, Switzerland had built a complex of fortifications. Although not as extensive as the Maginot or German lines, it was well placed, using the mountainous terrain and command of the few lines of communications through the passes.

The Maginot line has become a symbol. On one level it represents a defense that deluded its builders into thinking they need not do anything else but rely upon what seemed to be an impenetrable defense. It has also become a symbol or a shorthand expression for all of the reasons for France's defeat in 1940.

The irony is that had it been used properly, that is, supplemented with an acute understanding of what the enemy might do and not what the French wanted them to do, it might have been a symbol of victory. As designed, the Maginot line worked. It was the rest of France's strategy that failed.