In May 1940, the German Wehrmacht launched a lightning attack into France and within weeks destroyed the combined French and British armies. The rapid defeat is typically ascribed to a combination of the French High Command’s attempts to refight the methodical battle of World War I against Germany’s adoption of new mobile, all-arms warfare. Those philosophical factors certainly played a major role in the outcome, but something much more elemental and human may have been the deciding factor: fearless, intelligent and sometimes ruthless leadership at the point of contact.

In light of the dramatic collapse of the French armed forces in 1940, it is hard to imagine that up until that point they had been recognized—including by the Germans—as the military masters of Europe. France had emerged victorious over the Germans in the Great War, and imposed the Treaty of Versailles on Berlin, a punitive, humiliating armistice. In the first decade following the war, Germany had been limited to no more than one hundred thousand soldiers, no armored vehicles, and only one hundred “search and rescue” aircraft. France, on the other hand, rebuilt its armed forces following World War I, and in the early 1930s embarked on a major modernization drive, motorizing many of its infantry divisions and beginning to form armored units.

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Focused on preventing another German incursion into French territory, Paris had formed a military doctrine giving primacy to the defensive. The intent was to first blunt any invasion, and once the enemy had been sufficiently weakened, to transition to the offensive. In support of this philosophy, they built the now infamous Maginot Line of extensive defensive pillboxes and other heavily defended fortifications between France and her western neighbors. Senior officers of the High Command were confident their doctrine and defensive preparations would be successful against any German attack, most especially Commander of the Second French Army, Gen. Charles Huntziger.

In March 1940, less than two months before the German surprise invasion, Parliamentary Army Committee member Pierre-Charles Taittinger led a parliamentary delegation to inspect the defenses in Sedan, a city for whose defense General Huntziger was responsible. Taittinger prophetically reported, “In this region, we are entirely too much taken with the idea that the Ardennes woods and the Meuse River will shield Sedan and we assign entirely too much significance e to these natural obstacles. The defenses in this sector are rudimentary.” He wrote that he “trembled” at the thought the Germans might attack there. General Huntziger dismissed Taittinger’s warning entirely.

The chief comptroller of the Army asked General Huntziger if he put any stock in Taittinger’s report and the general replied, “Certainly not, the Germans are dead afraid of attacking.” On May 9, less than twenty-four hours before the invasion, Huntziger told his troops that “the German preparations which you have observed are only an exercise. The Germans are not crazy enough to take the additional risk of facing twenty-seven Belgian divisions”—though, to be fair, the confidence of the French High Command was not entirely without justification.

Prior to May 1940, the combined French and British forces had almost one thousand more tanks than the Germans, and French tanks had better armor and more powerful main guns. France was also the recognized global leader in artillery, and had a marked advantage over Germany in this regard. The French planned to rush large numbers of infantry divisions across the border of Belgium to take on the Wehrmacht as far forward as possible. They believed the forested and mountainous terrain in the Ardennes precluded the use of armor, and, along with the Maginot defenses, felt that light forces could protect that part of the front. The Germans, on the other hand, chose to do the opposite of what was expected.

Sending in large numbers of infantry and mechanized divisions into Belgium and the Netherlands, the Germans sought to make the Franco-British alliance believe its intelligence had been correct and that the main attack was coming in the north. Meanwhile, the main German attack came further to the south, in the Ardennes, with the bulk of their Panzer divisions. One of the primary objectives of the German armor was the penetration of the Meuse River at Sedan, just inside France. Commanding the forces at the tip of this attack was a man who would later distinguish himself as among the most accomplished battle leaders of the war: Lt. Col. Hermann Balck.

Balck—later to rise to command the Fourth Panzer Army—was tasked with leading the First Rifle Regiment (of First Panzer Division) across the Meuse near Sedan. The breakthrough he made across the river came as a result of thorough preparation, rigorous field training and, at the point of attack, ruthless, courageous leadership that inspired men to accomplish tasks they thought beyond their ability.

The French had been preparing to defend the Meuse for years, but the effort had taken on an earnestness in September 1939, when the Wehrmacht had unveiled its “blitzkrieg” tactics for the first time against Poland. The Nazis had defeated the Polish armed forces in just over four weeks, using a combination of mobile troops, armored firepower and paralyzing air attacks featuring the terrifying Stuka dive bombers. The French leaders continued to believe their defensive system and plans would succeed where the Poles had failed and inexplicably took no additional measures nor changed their existing plans. Commanders like Balck would soon expose just how wrong they were.

As part of the First Panzer Division, Balck’s First Rifle Regiment was selected to be the advance guard leading the division into enemy territory on the morning of May 10, 1940. After light resistance, Balck’s regiment reached the approaches to the Meuse outside of Sedan two days later, near 11:00 pm. Early the morning of May 13, however, a devastating French artillery barrage opened up. According to Balck’s memoir, Order in Chaos, the French bombardment was fierce and had a substantial demoralizing effect on his troops.

“I requested a Stuka attack on the French” artillery positions, he wrote, saying that the effect was overwhelming. “The French artillery was silenced and the mood of our troops turned into one of jubilation.” The positive feelings didn’t last long, however, as Balck ordered his men to march into the teeth of highly defended, concrete-reinforced French bunkers. The attack began to lose energy, and the troops were starting to drop from fatigue. At that point, Balck had a choice: conduct a tactical withdrawal with the frontline troops and order fresh soldiers into the fight, or press the attack and risk losing the objective.

“What was easy today, could cost a lot of blood tomorrow,” he said. “I walked off a distance, thought about it, and made a decision. We had to advance another ten kilometers into the enemy. My adjutant, Braune-Krikau, a resolute and courageous man with a keen military mind, said ‘sir, that would lead to the destruction of the regiment.’ ‘No,’ I replied. ‘It will lead to the destruction of the French.’” And so he was proven right.

Two days later, after pressing the attack again beyond what his men thought they could endure, Balck recorded that “there was no stopping them. With loud shouts echoing in the air, the thin, totally exhausted line of riflemen entered the village. Bouvellemont was ours. I had not miscalculated.” The last of the French resistance had been broken and the Meuse crossings secured. Balck was promoted to command a panzer brigade the next day and the fight continued to the Channel coast.

German leaders like Balck and the famous Erwin Rommel provided fearless, even brutal leadership from the front, inspiring their troops to overcome their fears and push their bodies well beyond what they thought they could endure. It is worth noting, however, that French soldiers did not enjoy the same caliber of leadership. Though many French troops fought with signal bravery, the same could not be said for the bulk of their officer leadership.

No one pushed the French troops to endure the unendurable, and when the crisis moment arrived, the French leaders often froze into inaction. One event perhaps best captured the spirit of the French leadership’s collapse, recorded by the Frenchman Marc Bloch (a French staff officer in 1940) in the book Strange Defeat.

Bloch was sent to the headquarters at Attiches, about eight miles from the Belgium border, to coordinate action with the British. While there, he saw a sight that haunted him. Bloch observed a French general sitting in a chair frozen “in tragic immobility, saying nothing, doing nothing, but just gazing at the map spread on the table between us, as though hoping to find on it the decision which he was incapable of taking.”

Though Germany eventually lost World War II and France again ended up on the victorious side, the leadership traits demonstrated before and during the battle in 1940 are textbook examples of what makes for great leadership—and what kind of leadership leads to defeat.