The Maginot Line was built by France in reaction to the slaughter of more than 1 million French soldiers in World War I. Before that war, the French military doctrine had been unchanged from when Napoleon I was emperor. If you wanted to win a battle, you attacked. Courage would overcome any enemy and guarantee victory. Admittedly, the doctrine had not worked so well even for Napoleon at the Battle of Nations or Waterloo, but France stuck with it. Then came World War I and the trenches. Attacking through barbed wire against modern artillery and machine guns proved fatal and useless. But it took the French generals almost two years and a mutiny to understand this.
The result of the French people’s revulsion to the horrific losses in World War I was to go to the other extreme. The leaders of postwar France decided that if total offense was a disaster, total defense must be the answer. France, since Vauban and Louis XIV, had been the leader in building fortresses, so fortresses it would be. The result was the construction of the Maginot Line at the cost of more than 3 billion francs. That amount today, were it an equivalent portion of the U.S. annual budget, would be more than $3,000,000,000: That’s $3 trillion. But the problem was not cost. The mistake that the French made was that the French built only half of the line.
The Maginot Line was not a single line of forts. It was rather a continuous series of defensive positions. The line included everything from small machine gun bunkers, some remote-controlled using periscopes, to massive artillery cupolas that would have been impressive on a battleship. In places, the defenses ran more than ten miles in depth. The forts were well stocked with everything from artillery shells to vintage wines and were ready to hold off any German attack for weeks without resupply. The Maginot Line was originally planned to run the entire length of the northern border of France. Half that border was with Germany. The other half ran along the border with Belgium. The first half, the portion that ran along the German border, was completed in the 1930s.
When construction of the Maginot Line reached the 150-mile border between France and Belgium, the government of Belgium objected. They refused to accept anything on the border because it inferred they would be abandoned by the French in the event of a German attack. But they also refused to allow the French to help them build anything along their border because it might serve as a provocation to the Germans. Belgium threatened that if the French built anything at all, they would ally themselves with Germany.
The French reaction was to do nothing. Even after Poland was invaded, there was no effort to add even the most rudimentary fortifications to the border that ran from the Ardennes to the Channel. Half of the French border was solidly fortified. The northern half, the route German armies had used almost every time they invaded France in the past thousand years, was left undefended. Eventually, the leaders of France justified stopping halfway by explaining that now they knew where the Germans had to attack since the Maginot Line was impregnable. Unfortunately for them, they were so right and so very wrong.
With half the border defenseless, the French and British agreed on a new strategy. When the Germans invaded Belgium, and only after they invaded, massive armies, waiting along the French border, would rush north and reinforce the Belgian army. The plan even worked. When the Sitzkrieg ended and the fighting between France and Germany began, the Nazis did attack northern Belgium; and like everyone expected, a day later the British Expeditionary Force and a substantial part of the French army hurried past the undefended French border and into defensive positions along Belgium’s waterways. While they did so, the Germans pressed only a little and mostly waited.
Once the British and French had committed dozens of divisions in Belgium, the Wehrmacht attacked through the virtually undefended Ardennes Forest. Undefended because the Maginot Line stopped short of it, and the French incorrectly assumed the forest was too dense for a major offensive to push through. They were wrong about it being impassable, and within weeks the main German offensive had reached the Channel. Hundreds of thousands of Allied soldiers were now trapped in Belgium. About 300,000 were eventually evacuated from Dunkirk, but more than that were left surrounded in northern Belgium while the panzers poured over the undefended portions of the French border and tore through France. Exactly one month after the Ardennes attack, the Nazis occupied Paris.
The part of the Maginot Line that was completed worked; what few Nazi assaults were made along it from Germany failed. But once France fell, most of the defenders had to surrender. Their guns faced the wrong way and many of their families were in German hands. The few fortresses that held out were not even attacked. Bulldozers were used to simply cover the turrets, ventilation shafts, and entrances with yards of dirt that turned the underground defenses into tombs.
But by allowing politics to overcome military sense, the incredibly expensive fortification failed to be more than a trap for the men manning it. Had the national wealth spent on constructing the Maginot Line been spent on tanks, planes, and artillery, the French army would have been immeasurably stronger. But the postwar wealth of France was squandered on a defensive line that by being incomplete accomplished nothing.
Had France ignored the irrational objections of Belgium and completed the Maginot Line, it might well have fulfilled its purpose. If, in 1940, the German panzer spearheads had to fight through a completed Maginot Line, their losses would have been staggering. The Nazis might still have defeated France in a much longer war, or they might not have, as the Blitzkrieg would have had little effect on mutually supporting and highly fortified positions. France might even have survived long enough to learn how to fight a modern war or force yet another stalemate on her German invaders.