THE MAGINOT LINE AND STRATEGIC PLANNING IN 1940
Often overlooked, fixed defenses had an important role in World War II. Of the many fortified positions that influenced the course of the war (from the Gustav Line in Italy to the numerous fortified islands in the Pacific) none was so extensive as France's Maginot Line. Nor have any
been so misunderstood in the popular imagination.
The seeds of the Maginot Line were sown in the trench slaughter of World War I. After much debate, in the late 1920s the French began to develop an elaborate system of fortifications on their frontier with Germany. Named after a war minister who had lost an arm at Verdun,
the Maginot Line was designed to prevent a direct German invasion of France by making such an attempt prohibitively costly in lives and time, permitting the French to husband their resources in the rear for a decisive counterstroke with mobile forces.
The basic concept was by no means as absurd as it would appear in retrospect. Among the greatest fortification experts in the world since the seventeenth century, the French were fully aware that their pro posed new fortified zone (it was not a "line" at all) was not impregnable.
But it would be so difficult to break that it would deter a German offensive into northeastern France. Unable to deliver a swift, decisive blow against it, the Germans would have to give up all thought of war with France, or accept a protracted war of attrition, or find an alternative
way to carry on the war. It was this last that French policymakers perceived as the most likely eventuality, specifically a German thrust into Belgium. And such an undertaking by a revitalized Germany would inevitably bring Great Britain into the war on the side of France, a necessity given France's manpower inferiority vis-A-vis Germany's.
So the principal function of the Maginot Line was to canalize a German offensive into Belgium, where it could be met by motorized French armies supported by British resources. This plan had the added (if unspoken) advantage of having the horrors of war visited upon Belgium rather than on France.
As built, the Maginot Line was a wonder to behold (as, indeed, its remains still are). It consisted of a loose belt of fortifications starting a few miles inside France. The defensive zone varied from five to ten miles in depth, liberally seasoned with sunken forts, redoubts, pillboxes, observation towers, tank traps, and other works. These works were designed to make maximum use of available ground, which already favored the defense, as northeastern France (Alsace and, Lorraine) is rather mountainous, often heavily forested, and occasionally marshy. Most positions (which were all gastight) were mutually supporting, and all were capable of holding out independently for extended periods if necessary. In some of the more densely fortified areas the principal works were linked together by underground railroads to permit the rapid movement of reinforcements and munitions.
Actually only about eighty-seven miles of the Franco-German frontier were covered by permanent works, at the extraordinary cost of 80.5 million francs per mile (about $20 million in 1930s dollars and 360 million in 2008 dollars). These works covered the most vulnerable areas. Less vulnerable areas (such as the thirty-mile Sarre Gap) were to be protected in time of war by demolitions, waterlines (such as the Rhine itself), and inundations, covered by combat troops
in field fortifications. Despite the enormous expenditure, over 7 billion francs (nearly $30 billion in today's dollars), the system was not fully complete by 1940, but sufficiently so to have precisely the deterrent effect for which the French had hoped.
There seems little doubt that the Maginot Line was more or less impenetrable from a frontal attack, at least at a price the Germans were willing to pay. Certainly German war planners proposed nothing more than demonstrations against the line in the event of war, preferring instead
to go into Belgium, precisely as the French expected. French planning for the anticipated German offensive into Belgium presumed that the Germans would come more or less as they had in 1914, a massive wheeling drive across the northern Belgian plain and then southward into France. To meet this, the French allocated the best part of their army (about thirty divisions, including virtually all of their dozen motorized and light armored divisions) to their left flank, from whence, in company with the fully motorized British, they would boldly advance into Belgium
in the event of a German invasion, to meet the enemy along the Dyle River, east of Brussels for a decisive battle.
In their initial planning for their 1940 offensive against France, the Germans actually came up with a plan that more or less was what the French expected of them, a holding action against the Maginot Line with a straightforward drive across the Belgian plain, taking advantage of the
superior mobility and effectiveness of their seventeen armored and motorized divisions. The objective was to secure as much of the country as possible in anticipation of future offensives. Although this plan met with the approval of the General Staff, Hitler was dissatisfied. The fiihrer
wanted a quick win to maintain his popularity, and the plan suggested a protracted struggle. A relatively junior officer, Erich von Manstein, thereupon came up with a more complex, bolder, and riskier plan.
Under the new plan, a portion of the army, including some armored and motorized formations supported by airborne troops, would attack directly into Belgium and the Netherlands as a feint to draw Allied reserves northward. Meanwhile the bulk of the army would attack through the Ardennes, a rugged, heavily forested region covering most of Luxembourg plus adjacent portions of France and Belgium.
The idea was to slice through the Allied forces, creating an enormous pocket in Belgium, perhaps winning the war in one grand offensive. This new plan appealed to Hitler's sense of grandeur, despite the risks which were considerable. Many years earlier Marshal Philippe Petain, hero of World War I, had been asked about the possibilities of a German offensive in this very area, to which he replied, "The Ardennes are impenetrable, if adequately defended." He was right, for
the Ardennes are traversed by few roads, and those are narrow and easily blocked by light forces, provided there were enough of them.
When, on the morning of May 10, 1940, the French General Staff learned that the Germans had launched their long-anticipated offensive, one officer said to Chief of Staff Maurice Gamelin, "So it is the Dyle Plan, no?" Gamelin looked up and replied, "What else can we do?"
And, indeed, everything went according to plan, the German plan. At the first sign of the German offensive (the feint into the Netherlands and northern Belgium) the French and British leapt forward into Belgium. Elements of the French Seventh Army, on the extreme left, advanced something like 150 miles in the first forty-eight hours, one of the most impressive motor marches by a large force to that time. By nightfall on May 12 the Allied spearheads were well into the
Netherlands and Belgium. And at that same moment the German main blow fell. Nearly a dozen armored and motorized divisions emerged from the Ardennes to fall upon second-line French forces near Sedan. The German movement had not only been undetected but virtually unimpeded, for the Ardennes had hardly been "adequately defended."
Allied strength in the region consisted of two Belgian light infantry divisions and some French cavalry, who despite heroic efforts only managed to slow the Germans down by a few hours.
The French defenses at Sedan crumbled quickly under the extraordinary strength and violence of the German offensive. Within a day the Germans were across the Meuse and heading west through a fifty-mile gap they had torn in the French front. A few days more and the Germans were halfway across France despite often heroic attempts to impede them. And late on May 20 the Germans reached the English Channel near Abbeville, effectively pocketing nearly forty British, French, and Belgian divisions.
Then came the high drama of Dunkirk, the German offensive southward, the fall of Paris, and the surrender of France. And through it all the Maginot Line remained virtually unscathed. So the Maginot Line had worked, "worked" in the sense that it had canalized the German offensive into Belgium. Despite this "success" one somehow suspects that the French might have spent their money better elsewhere.
Article from Dirty Little Secrets of WWII.