BLITZKRIEG

“You’d think, to hear some people talk, / That lads go west with sobs and curses, / And sullen faces white as chalk. / Hankering for wreaths and tombs and hearses. / But they’ve been taught the way to do it / Like Christian soldiers; not with haste / And shuddering groans; but passing through it / With due regard for decent taste. —from How to Die by Siegfried Sassoon

Sometimes referred to as “the father of the blitzkrieg’, the German Lieutenant-General Heinz Guderian, evolved a theory for fielding a highly mechanized mobile army and then expounded on it in his book Achtung Panzer! which impressed the German Chancellor Adolf Hitler who, in 1934, gave Guderian the task of perfecting the fighting technique and capability of Germany’s armoured fighting forces, supported by infantry and aircraft. This resulted in the famous blitzkrieg (lightning war) method of warfare. The concept and strategy of spearheading fast-moving tanks, followed by motorized infantry and supported by dive-bombers was first proposed by British Army Colonel John Fuller, Chief of Staff of the British Tank Corps. In frustration over the way in which tanks were used in WWI, Fuller devised a plan calling for long-range mass tank attacks supported by strong air, motorized infantry, and artillery. He developed the idea in considerable detail in his books Reformation of War (1923) and Foundation of the Science of War (1926). Fuller: “Speed, and still more speed, and always speed was the secret … and that demanded audacity, more audacity and always audacity.” The British Army showed little interest in Fuller’s ideas, but they aroused considerable interest in Germany where the military devoted considerable time to the study of Fuller’s books and the government eagerly ordered the production of new tanks.

Prior to the First World War, many Germans had perceived their country as being surrounded by threatening enemy nations with greater resources. German strategists of the time, and Count Alfred von Schlieffen in particular, believed that Germany could not win in a long, protracted military struggle against such adversaries. He believed that, for Germany to achieve victory against those enemies, she would have to defeat them quickly and decisively and, as she would always be outnumbered by her enemies, she would have to be fully prepared for such conflicts with better quality training, equipment, planning and execution than her opponents could field. Schlieffen created a doctrine for the German Army whereby it would outfight its opposition using great speed of manoeuvring and attacking the enemy where he was weakest. He wanted to wrong-foot the enemy, forcing reaction for which the enemy was unprepared, and always maintaining the initiative. He proposed achieving this through the use of a flexible command system as proposed earlier by Helmuth von Moltke the Elder. The German Army would in time accept that, as conditions on the battlefield tended to change quickly and orders from higher command were frequently overtaken by events, it was desirable to encourage field commanders to make quick, independent, opportunistic decisions without waiting for orders from their superiors. In so doing, the Army anticipated creating many new aggressive, flexible leaders in command positions.

Schlieffen, and his successor Helmuth von Moltke the Younger, gradually trained the German Army in what they called the “war of manoeuvre”, and by the early months of WWI German Army units were mostly outfighting the Allies in their early encounters. But in 1914 when that war began, the German Army was not mechanized and was unable to move long distances rapidly. Thus, it was unable to achieve truly decisive victories and had to reluctantly settle into trench warfare.

The problem of the trench stalemate was finally addressed by the German officer corps in the spring of 1918 when they elected to apply Schlieffen’s operating principles to the smaller army units as well as the large ones. They chose to decentrailize command and at the same time increase the firepower of the infantry. They wanted to create a lot of platoon-sized units that could act independently in combat, with freedom to engage as they thought most appropriate in the situation.

“The European war will be an industrial war of aircraft, tanks and movement.”— Dwight D. Eisenhower, while he was an aide to General Douglas MacArthur in the Philippines

The term blitzkrieg was actually coined by western journalists during the German invasion of Poland in 1939 and its meaning has usually been linked with a series of rapid, decisive brief battles intended to knock out or destroy the enemy force before it can fully mobilize and react. Functionally, it has been generally accepted to be a coordinated military effort by tanks and other armoured vehicles, mobilized infantry, artillery, and aircraft to quickly establish overwhelming combat superiority and break through the enemy lines. An additional element that the Germans brought to the concept was psychological. The employment of terror lending further chaos, confusion and enhancing the fear of the sudden attack was exemplified in the use of the noise-making sirens fitted to the Junkers Ju 87 Stuka dive-bombers the Germans used in support of their armoured and infantry forces.

Early references to the term blitzkrieg are relatively rare and do not occur in handbooks of German Army or Air Force doctrine. German press uses of the term were rare and did not occur before 1939. A few early references exist relating to German efforts to break the stalemate and win a quick victory in the First World War, but were not specifically related to the use of armoured or mechanized forces or aircraft. It was used in the context of Germany needing to develop self-sufficiency in food and other areas in the event of her becoming involved in a wide, protracted war. A 1938 article appeared on the matter of Germany developing the capability to launch a rapid strategic knockout blow, but acknowledges the difficulty of accomplishing such a result in a land attack in modern circumstances, especially relative to the problems posed by fortification systems such as the Maginot Line unless considerable surprise is achieved. There is also a reference in a book by Fritz Sternberg, Die Deutsche Kriegsstärke (German War Strength), published in 1939, and an English edition published in 1938 called Germany and a Lightning War, in which the author uses the term blitzkrieg arguing that Germany was not economically able to sustain a protracted war, but might be able to win a quick one. He does not elaborate on any tactical or operational considerations, nor does he advance the notion that the German armed forces have developed such a method of warfare. Adolf Hitler supposedly said in a November 1941 speech: “I have never used the word blitzkrieg, because it is a very silly word.”

In the terrible, stalemated trench warfare of the First World War, kill zones had been established with barbed wire and the brutal crossfire of machineguns keeping either side from making a breakthrough to the enemy lines. In an inspired effort to end the stalemate, the British introduced the first tanks to the battlefields of France. These early armoured vehicles were essentially invulnerable to machine-gun fire and were able to cross most trenches and breach the barbed wire, breaking a pathway for the Allied infantry troops to follow in their wake. Initially, they achieved some success in penetrating the German lines, and certainly managed to shock and frighten the Germans in the early days of their entry in the war zone. The British, though, were not able to produce enough tanks by the war’s end to demonstrate the sort of capability that was to come in later years. But the appearance of those early tanks certainly intrigued the Germans with the battlefield potential of the new weapon.

With German defeat in the First World War came the limitations set by the Versailles peace treaty, among them the limitation of any new German army to a total of 100,000 men with no more than 4,000 officers. The framers of the treaty reasoned that such a limit would effectively prevent Germany from ever again deploying the masses of troops that had been the basis of her battlefield strategy. Technically, the German General Staff had been abolished by the treaty, but in reality it continued to function in the guise of the Truppenamt (troop office), the secret General Staff. Comprised of veteran staff officers, these men drew on their WWI experience to draught reports that resulted in training manuals and doctrine which led to new standardized procedures that would be employed in WWII.

From 1919 through 1935 that new German army was called the Reichswehr (Reich Defence). In 1935 it was renamed the Wehrmacht (Defence Force). Notable was the criticism levelled at much of the German officer corps its essentially collective failure to grasp many of the technical advances of the First World War, including that of the machine-gun, and for placing tank design and production on such a low priority. Most of these officers studied in military technical schools during the period of rebuilding the army after the war. Much of their focus centred on the infiltration tactics developed by the Germans in WWI, and the use of decentralized groups to strike at weak positions and attack rear-area communications facilities, supported by coordinated artillery and air attacks which were a prelude to bombardment by large infantry forces to destroy the centres of resistance—all of which would become the foundation of German Army tactics in WWII.

Among the first moves towards the direction of a blitzkrieg approach to future warfare came when the Chief of Staff of the new German Army, Generaloberst Hans von Seekt directed a shift in doctrine from what he believed to be excessive emphasis on encirclement to something based on speed and mobility. Von Seekt would develop the doctrine for the operation of the Wehrmacht in WWII. It was published by the army in 1921 under the title Command and Combat with Combined Arms.

In 1928, Seekt’s book Thoughts of a Soldier was published. In it he was critical of the huge conscript armies of the recent past, claiming that technical science and tactical skill would win the wars of the future: “The whole future of warfare appears to me to lie in the employment of mobile armies, relatively small but of high quality, and rendered distinctly more effective by the addition of aircraft, and in the simultaneous mobilization of the whole forces, either to feed the attack or for home defence.”

Seekt had the problem of maintaining the morale of the German armed forces in spite of the limitations imposed by the Versailles treaty. He began by reshaping the German Army into a thirty-five-division mobile shock force. His approach was called Bewegungskrieg (manoeuvre warfare) which actually introduced a leadership system of mission tactics where local commanders were authorized to take immediate, on-the-spot decisions about how to accomplish the tasks of their missions. Incorporating the ideas of Schlieffen, this system was vital to the success of the blitzkrieg concept, providing a powerful advantage to the Germans over their adversaries. It was key to the operation of the “lightning war” technique, but in early 1942 the OKW (Oberkommando der Wehrmacht or High Command of the Third Reich armed forces) called a halt to it in the belief that there was too much risk involved in allowing German Corps and Army Groups to be commanded and run wholly independently by a single field commander. When the German Army of 1940 went to war in the west, it did so on an offensive doctrine built around swift decision-making, rapid manoeuvring and decentralized fighting. It was influenced in large part by Schlieffen’s emphasis on high speed action, encirclement, flanking attack, and the vital importance of achieving decisive combat results. It included his tactical concepts for the operational level as devised during the First World War and incorporated the developing technology of the 1920s and 1930s of tanks, motorized armoured vehicles, aircraft, and radio communications. Most of the military and political leaders of Germany in the 1930s were in agreement that application of the new offensive doctrine was as important at the tactical operating level— speedy manoeuvre and independent fire—as it was at higher levels. In 1940 at least, that application enabled elements of the German Army to prevail, outfighting the Allies (even when outnumbered in equipment and personnel), and frequently leading to collapsing Allied resistance.

They called it the “Phoney War”, the period between the German occupation of Poland in the autumn of 1939 and the German invasion of Norway in April 1940. In that strange time the British were persuaded by the French to hold off bombing targets in Germany. The French worried about German reprisals and tried to prepare themselves to resist a German move against France, pinning their hopes and their future on their Maginot Line of fortifications. They, like the British, and the Americans, seemed stuck in an old set-piece battle mindset in which their mechanized forces were mainly meant to keep up momentum on the battlefield, much as it had been in the First World War. They showed little interest in concentration of forces, deep penetration, or the use of combined forces.

The British continued their tank development and to an extent maintained an interest in a mechanized role for their army in reaction to the heavy casualties and lack of progress on the battlefields of WWI. Still, in this period they failed to develop a strategic policy in line with their technical developments. One man among the Allies who did think along the same general progressive line as Seekt and Guderian was then Colonel Charles De Gaulle. In that period De Gaulle wrote a book called Vers l’Armee de Métier (Towards the Professional Army) in which he advocated the concentration of armour and aircraft and maintained that France could no longer have the sort of large army with which it had fought WWI. He believed in the concept of using tanks, mechanized forces, and aircraft to enable a smaller number of well-trained and well-equipped personnel to achieve far more on the battlefield. He did not endear himself to the French High Command with his perspectives, but he may well have influenced Guderian.

Meanwhile, in the Soviet Union a prominent Red Army officer, Marshal Mikhail Tukhachevesky, was developing the notion of deep operations in warfare, based on his experiences in the Polish-Soviet conflict. Mindful of the limitations of cavalry and infantry, Tukhachevesky was promoting the use of mechanized formations and large-scale industrialization to support them. Unlike the standard definition of the blitzkrieg tactic, however, the Soviet concept advocated total war rather than limited operations and several large-scale simultaneous offensives instead of a single decisive battle.

Another condition of the 1919 Treaty of Versailles prohibited Germany from operating any form of air force. It also prohibited the production or import of any form of aircraft in Germany. In 1922, that clause was modified to allow the production of civilian aircraft in Germany and, a year later, the control of German airspace was returned to the nation. Production and operation of any aircraft for military use was still prohibited. But the Reichswehr was sensitive to the evolution of aircraft and tactics for aerial warfare and was not willing to lag behind the rest of the world, regardless of the Versailles treaty. It began with the normalization of relations with the Soviet Union in 1922 through another treaty.

Germany had been required to pay reparations after WWI and, when in 1923 she defaulted on those reparations, French and Belgian forces occupied part of the Ruhr Valley. The action shifted the German position on obeying the terms of Versailles, triggering an order by the German Army for 100 new aircraft from the Fokker company in the Netherlands, fifty of the planes being the new Fokker D.XIII. The following year, the crisis in the Ruhr ended and the new Fokker planes were due to be delivered shortly. The Germans approached the Soviets about the possibility of developing new aircraft in the Soviet Union and the Russians were interested.

June 1924. The Germans assigned retired Colonel Hermann von der Lieth-Thomsen as permanent representative of the Truppenamt, in Moscow. Seven German flight instructors were then sent to work with the Red Air Force, and in the following April, Leith-Thomsen signed a contract establishing the German fighter pilot school at Lipetsk, some 230 miles from Moscow. By spring 1926 extensive construction work had been completed and the training of new German fighter pilots and fighter ground personnel began. The pilots and ground personnel would also serve as instructors upon the formation of the new German Air Force in 1935. Training continued at the Lipetsk base until 1933 when the Nazis came to power in Germany and their ideological differences with the Soviets led to the closure of the Lipetsk school and the ending of the Russo-German pilot training arrangement.

With the Spanish Civil War in 1936, the German Panzer Battalion 88—three companies of Panzer I tanks—were provided by the Nazis to the Spanish Nationalists, while the new German Luftwaffe sent squadrons of dive-bombers, fighters and transport aircraft to action in the conflict, aircraft and personnel of the Condor Legion, which was made up of volunteers from the air force and the army. They served in Spain from July 1936 to March 1939, and there developed methods of “terror” bombing, demonstrated infamously in the raid on Guernica. The aircraft units of the Condor Legion were commanded in Spain by Hugo Sperrle and the ground units by Wilhelm Ritter von Thoma. The controversial attack on Guernica is thought by many historians to have been intended as a demonstration of the worth of the Condor Legion’s contribution to the Nationalist cause.

The application of Guderian’s concept of armoured warfare in Spain was, in his words, “on too small a scale to allow accurate assessments to be made.” That would have to wait until the start of the Second World War in 1939. The first testing of the Ju 87 Stuka dive-bomber was conducted impressively by German volunteers in the Spanish Civil War, an effective proving combat environment for the various new German aircraft and tactics.

On April 9, Hitler’s forces invaded Norway and Denmark, in part to isolate Sweden whose iron ore resources he coveted.

When German forces had invaded Poland in early September 1939, many newspaper writers in the west referred to the action as a blitzkrieg but, in fact, the action was mainly a conventional envelopment. The three primary panzer units were dispersed rather than concentrated. The use of tanks, dive-bombers and infantry was largely conventional. According to historian Matthew Cooper, “… throughout the Polish campaign, the employment of the mechanised units revealed the idea that they were intended solely to ease the advance and to support the activities of the infantry … thus, any strategic exploitation of the armoured idea was still-born. The paralysis of command and the breakdown of morale were not made the ultimate aim of the German ground and air forces, and were only incidental by-products of the traditional maneuvers of rapid encirclement and of the supporting activities of the flying artillery of the Luftwaffe, both of which had as their purpose the physical destruction of the enemy troops.”

The first major examples of employing the blitzkrieg idea came with the German invasion of France and the subsidiary thrusts into Belgium and the Netherlands. Operation Fall Gelb (Case Yellow) began as a swift move against Belgium and the Netherlands by German paratroopers and two armoured corps on 10 May 1940. The German armoured units, against all expectations of the French, drove quickly through the Ardennes, cutting off and surrounding Allied forces that had moved into Belgium. The Allies had fallen into Hitler’s trap.

From the personal papers of Generalfeldmarschall Erwin Rommel, commander of the 7th Panzer Division during the German invasion of France in 1940, and who would later be known as ‘The Desert Fox’ for his leading role in the North African campaign, and his command of the German forces defending against the Allied cross-Channel invasion of June 1944. In an extract from his journal, Rommel wrote of the blitzkrieg drive of his panzers skirting the Maginot Line fortifications and racing to attack French forces near the River Meuse on the Belgian border: “Rothenburg [one of his tank commanders] now drove off through a hollow to the left with the five tanks which were to accompany the infantry, thus giving these tanks a lead of 100 to 150 yards. There was no sound of enemy fire. Some twenty to thirty tanks followed up behind. When the commander of the five tanks reached the rifle company on the southern edge of Onhaye wood, Colonel Rothenburg moved off with his leading tanks along the edge of the wood going west. We had just reached the southwest corner of the wood and were about to cross a low plantation, from which we could see the five tanks escorting the infantry below us to our left front, when suddenly we came under heavy artillery and antitank gunfire from the west. Shells landed all around us and my tank received two hits one after the other, the first on the upper edge of the turret and the second in the periscope.

“The driver promptly opened the throttle wide and drove straight into the nearest bushes. He had only gone a few yards, however, when the tank slid down a steep slope on the western edge of the wood and finally stopped, canted over on its side, in such a position that the enemy, whose guns were in position about 500 yards away on the edge of the next wood, could not fail to see it. I had been wounded in the right cheek by a small splinter fron the shell which had landed in the periscope It was not serious, though it bled a great deal.

“I tried to swing the turret round so as to bring our 37mm gun to bear on the enemy in the opposite wood, but with the heavy slant of the tank it was immovable.

“The French battery now opened rapid fire on our wood and at any moment we could expect their fire to be aimed at our tank, which was in full view. I therefore decided to abandon it as fast as I could, taking the crew with me. At that moment the subaltern in command of the tanks escorting the infantry reported himself wounded, with the words: ‘Herr General, my left arm has been shot off.’ We clamored up through the sandy pit, shells crashing and splintering all round. Close in front of us trundled Rothenburg’s tank with flames pouring out of the rear. The adjutant of the panzer regiment had also left his tank. I thought at first that the command tank had been set alight by a hit in [the] petrol tank and was extremely worried for Colonel Rothenburg’s safety. However, it turned out to be only the smoke candles that had caught light, the smoke from which now served us very well. In the meantime Lieutenant Most had driven my armoured signals vehicle into the wood, where it had been hit in the engine and now stood immobilized. The crew was unhurt.”

From behind the structures of the Maginot Line, Rommel’s forces raced north to attack the fortifications from the rear: “The tanks now rolled in a long column through the line of fortifications and on towards the first houses, which had been set alight by our fire. In the moonlight we could see the men of 7th Motorcycle Battalion moving forward on foot beside us. Occasionally an enemy machine-gun or anti-tank gun fired, but none of their shots came anywhere near us. Our artilllery was dropping heavy harassing fire on villages and the road far ahead of the regiment. Gradually the speed increased. Before long we were 500-1,000-2,000-3,000 yards into the fortified zone. Engines roared, tank tracks clanked and clattered. Whether or not the enemy was firing was impossible to tell in the ear-splitting noise. We crossed the railway line a mile or so southwest of Soire le Chateau, and then swung north to the main road which was soon reached. Then off along the road and past the first houses.

“The people in the houses were rudely awoken by the din of our tanks, the clatter and roar of tracks and engines. Troops lay bivouacked beside the road, military vehicles stood parked in farmyards and in some places on the road itself. Civilians and French troops, their faces distorted with terror, lay huddled in the ditches, alongside hedges and in every hollow beside the road. We passed refugee columns, the carts abandoned by their owners, who had fled in panic into the fields. On we went, at a steady speed, towards our objective. Every so often a quick glance at the map by a shaded light and a short wireless message to Division H.Q. to report the position and thus the success of 25th Panzer Regiment. Every so often a look out of the hatch to assure myself that there was still no resistance and that contact was being maintained to the rear. The flat countryside lay spread out around us under the cold light of the moon. We were through the Maginot Line! It was hardly conceivable. Twenty-two years before we had stood for four and a half long years before this self-same enemy and had won victory after victory and yet finally lost the war. And now we had broken through the renowned Maginot Line and were driving deep into enemy territory. It was not just a beautiful dream. It was reality.”

All roads in the area were jammed with refugees fleeing the front. Thousands of French and British troops trying to reach the front were caught up in the massive retreating mixture of civilians and military and were pushed back. German Stuka dive-bombers appeared and repeatedly strafed the masses on the roads.

In their headlong race to the seacoast, the German tanks and armoured vehicles were suddenly and mysteriously halted on 21 May by a High Command order. In this thrust they encountered and encircled thirty-five Allied divisions, including the British Expeditionary Force.

As the extremely mobile Germans efficiently threw the British and French troops back towards the Channel coast the British government chose to evacuate the British Expeditionary Force and several French Army units from the beaches at Dunkirk, an operation known as Dynamo which lasted from 27 May to 4 June. In the action, some 40,000 men, survivors of the French 1st Army, fought a desperate delaying action against seven German divisions— three of them armoured—which were attempting to block and destroy the Allied armies near Dunkirk. Of them Winston Churchill said. “These Frenchmen, under the gallant leadership of Molinié, had for four critical days contained no less than seven German divisions which otherwise could have joined in the assaults on the Dunkirk perimeter. This was a splendid contribution to the escape of their more fortunate comradexs of the BEF.”

Still outstanding in British memory is the amazing rescue effort mounted by the rapidly assembled fleet of some 700 merchant marine boats, pleasure craft, fishing boats, and Royal National Lifeboat Institution lifeboats, together with forty-two Royal Navy destroyers. By the final day of the evacuation, 338,226 soldiers (198,229 British and 139,997 French) were rescued from the beaches, the harbour mole, and from where they had waded out into shoulder-deep water. The various small vessels were mostly manned by civilians and the effort is today known as the “miracle of the little ships.”

Following the Dunkirk evacuation, France was essentially on her own and on 5 June the Germans began the Fall Rot (Case Red) against the seriously depleted French armed forces. French resistance at the start was staunch, but the vastly greater enemy air superiority soon overwhelmed those resisting forces and their artillery. The vaunted Maginot Line defensive fortifications were smoothly outflanked by the well-organized, highly mobile German armoured forces and the French defence was nearly over. The German forces rolled into Paris meeting little real resistance on 14 June and their commanders soon met with French officials, the two sides talking about setting up an alliance. French president, Marshall Philippe Pétain sued for peace with the Third Reich. Pétain, who had led the French to victory at the Battle of Verdun in WWI, had to cede three-fifths of French territory to German control. Hitler insisted, too, that the Franco-German armistice agreement be signed in the same railway car in which Germany had been forced to formally accept defeat in that war. In only a few weeks the German Army had overwhelmed the army of the French Third Republic and in the process, caused a stunned Britain, France’s ally, to withdraw the entire British Expeditionary Force from the European continent.

In the aftermath of that withdrawal, both the British and the French were left pondering how and why they had got it all so wrong. They had anticipated yet another long, drawn-out WWI-style defensive struggle in which they would prevail. They had seen themselves as being well-equipped, welltrained, and well-prepared to fight a modern war against the Wehrmacht. They hadn’t banked on the Germans showing up with the blitzkrieg tactic. They had certainly counted on the Maginot Line along France’s heavily fortified border with Germany, to their cost and embarassment. The British and French had believed that the battle of this new war would evolve slowly and be fought traditionally, with infantry and artillery. Instead, they found in the Germans an enemy who came to fight an offensive war and with the equipment, skill and determination to win victory quickly.

In analyzing the defeat of the Allies in France and Belgium, Allied military observers ultimately attributed it to the blitzkrieg, the new type of warfare effectively implemented in the campaign by the German Wehrmacht. They pinned the success of the tactic to the enemy’s brilliant use of the new technology of the tank and the dive-bomber.

Adolf Hitler issued a series of directives—his instructions and strategic plans—beginning in August 1939 and covered a wide range of topics, from the detailed direction of military units, to the governance of occupied territories. The subject of his Directive No. 6, issued 9 October 1939, was plans for the offensive in the west. His enduring interest had been in major military campaigns to defeat the countries of western Europe, preparatory to conquering much of eastern Europe. In doing so, he hoped to avoid a war on two fronts. His directive No. 6, though, appears to have been founded on the probability that several years would be needed before German military power would be capable of such adventures and that, for the present, only more limited objectives were realistic. Such objectives included an imminent conquest of the Low Countries, with the aims of improving Germany’s ultimate ability to sustain and survive a protracted conflict, minimize the threat he perceived from neighbouring France, and prevent or minimize the threat of Allied aircraft bombing the vital Ruhr Valley industrial complex. Further, it was intended in part as a foundation for a German air and sea campaign against Britain. In the coming action he wanted to occupy as much of the area of northern France along the German border as possible. Ironically, on the same day he issued this directive, he discovered that his notion of implementing the action against the Low Countries and northern France within a few weeks was, in fact, illusory, as he learned that he been misinformed about the current strength of his forces. The Polish campaign had brought a heavy repair and servicing requirement for Germany’s tanks and motorized infantry, and ammunition supplies were essentially depleted.

 19 October 1939. Generalstabschef der Heeres (Chief of Staff of the German Army) Franz Halder, presented the initial plan for the Low Countries campaign, Fall Gelb (Case Yellow). It proposed a frontal attack in which upwards of a half million German soldiers might be sacrificed in order to shove the Allies back to the River Somme, and the consequence would include the depletion of the army’s strength for upwards of two years, before Germany would be able to launch a main attack against France. Hitler and many of his principle military commanders were profoundly disappointed in the Halder plan. Hitler then wanted to attack, whether his forces were prepared or not, on the basis that he might achieve a quick and easy victory by catching the Allies unprepared. Some of his commanders persuaded him to delay such a move while preparations were quickly advanced or the weather improved. Prinicipal among them was his commander of Army Group A, General Gerd von Rundstedt, who disagreed strongly with the Halder plan. He believed that the main body of the Allied forces had to be encircled and destroyed in the Sedan region, which just happened to be the main assignment area for Rundstedt’s Army Group. He put his chief of staff, Generalleutnant Erich von Manstein, on the task of devising a new plan around his objective.

Manstein was headquartered in Koblenz where he was at work on the new plan and, at the same time, Generalleutnant Heinz Guderian, commander of the elite armoured XIX Army Corps, was also located in the city. Manstein’s plan called for a powerful move north from Sedan to attack the rear of the main Allied forces in Belgium, and he invited Guderian to contribute ideas to the plan during informal discussions. Heinz Guderian offered a somewhat radical notion in which his own army corps, together with the majority of the Panzerwaffe tanks would be concentrated at Sedan. Rather than heading north, he proposed a rapid, deep-penetration strategic movement towards the English Channel, without waiting for the infantry divisions. Guderian thought that such an action might well cause a strategic collapse of the enemy forces and avoid the excessively high casualties projected for the German Army in such battles. Guderian’s ideas, however, often met with considerable doubt among the German General Staff, and this was no exception. But Guderian knew his fundamentals well, including the terrain involved, and he was wholly confident in the Manstein plan.

Sensitive to the mixed reviews Guderian’s ideas normally engendered in high Army circles, Manstein wrote a series of memos outlining aspects of his plan, while never mentioning Guderian’s name as a contributor to it. The German High Command rejected all of this memoranda and did not forward the content to Hitler. In fact, Halder, supremely protective of his own plan for the campaign, relieved Manstein and reassigned him to command an army corps in Prussia on 27 January 1940, in order to reduce Manstein’s influence over the campaign. Manstein’s staff then informed Hitler of their commander’s plan on 2 February. On 17 February, Hitler conferred with Manstein, High Command Chief of Operations General Alfred Jodl, and General Rudolf Schmundt, the German Army Chief of Personnel. At the end of the meeting, Hitler seemed in complete agreement with Manstein and was then hopeful of victory.

But Halder was determined not to allow the independent strategic penetration by the seven armoured divisions of Army Group A, and had that aspect of the new plan removed on 24 February, much to the anger of Guderian. As the plan continued to evolve, it drew intense criticism from many of the German generals and much of the officer corps who thought it irresponsible and potentially catastrophic should the Allies fail to react as the plan anticipated. Halder ignored their objections.

The Netherlands and Belgium were still neutral in the autumn of 1939, though they had secretly arranged possible future cooperation with the Allies, should the Germans invade their territories. While the Germans were busy occupying Poland, Maurice Gamelin, Supreme Commander of the French Army, had suggested that the Allies take advantage of that fact and utilize the Low Countries as bases from which to attack Germany, but the French government chose not to pursue the suggestion.

Following the German invasion of Poland, French forces advanced along the Maginot Line into the Saar, fielding some 2,500 tanks and fully ninety-eight divisions, most of them reserve and fortress formation elements, against forty-three German divisions, thirty-two of them reserves, and no tanks. The French force reached what was then an undermanned Siegfriedstellung, the Siegfried Line, the Westwall defensive forts and tank defences along the German border with the Netherlands, Belgium, Luxembourg, France, and Switzerland. Had the French chosen to advance they probably would have readily penetrated the defences and continued their Saar offensive, but instead they elected to force the Germans into an offensive posture and withdrew to their own lines.

The Belgian consul-general in Cologne was receiving intelligence reports as the winter of 1939-40 set in. The reports indicated the direction of advance intended in the Manstein plan, as well as the expected concentration of German forces along the Luxembourg and Belgian borders. Persuaded by these reports, the Belgians believed that the Germans would push through the Ardennes and on to the English Channel, cutting off the Allied armies in northeastern France and Belgium. They believed too, that the Germans would use airborne and glider troops behind the Allied lines to neutralize fortifications in Belgium. When the Belgians passed the information on to the French and British governments, the warnings were ignored. By March, intelligence sources in Switzerland had detected up to seven panzer divisions on the German border between Belgium and Luxembourg, as well as additional motorized divisions. The French government was also informed then about German construction of pontoon bridges on the River Our along the German-Luxembourg border. The French were warned on 30 April that the German assault would come on the River Meuse at Sedan between 8 and 10 May.

Estimates of the German military strength in early May 1940 indicate 4,200,000 army, 1,000,000 air force, 180,000 navy, and 100,000 Waffen SS. Of these, the personnel then engaged in Poland, Norway, and Denmark had reduced the total of army men available for the coming offensive to about 3,000,000 and were set to be organized as 135 divisions for the offensive with forty-two divisions in reserve. The available German weaponry included 2,439 tanks and 7,378 artillery guns. Roughly half of all the soldiers had had only a few weeks of training and nearly half of the army at that time was at least forty years old. Popular belief is that the entire army was motorized at that point; in fact just ten percent was motorized then and amounted to 120,000 vehicles and many horse-drawn conveyances. The French Army then had 300,000 vehicles, and the British Army was well-equipped with vehicles. Of the German divisions available for the offensive, only about half were adequately equipped and actually combat-ready. The limited number of well-equipped and trained “elite” divisions were offset by the many second and third-rate divisions.

Organizationally, three principal groups comprised the German Army then. Gerd von Rundstedt commanded Army Group A: forty-five and a half divisions, of which seven were armoured. His assignment was to cut through the Allied defences in the Ardennes and his Group contained three Panzer corps, the XV allocated to the 4th Army, and XXXXI (Reinhardt) and XIX (Guderian) which were connected to the XIV Army Corps of two motorized infantry divisions, which were operationally independent as the XXII Corps (Panzergruppe Kleist).

Fedor von Bock commanded Army Group B comprised of twenty-nine and a half divisions, of which three were armoured. Von Bock’s assignment was to advance through the Low Countries, drawing northern units of the Allied armies in traps. His force was made up of the 6th and 18th Armies.

Wilhelm Ritter von Leeb was in command of the eighteen divisions of Army Group C and his role was to prevent any flanking movement developing from the east, as well as the launching of small holding attacks against the Maginot Line and the upper Rhine. His force consisted of the 1st and 7th Armies.

Unlike the Allied armies, the German Army relied operationally on combined arms combat; on fast, very mobile offensive capability and well-trained infantry, artillery, engineering, and tanks combined as Panzer divisions. Good communications was key to the successful operation of the German land forces. This effective communication allowed the panzers to move into and exploit combat situations faster than their foes could react. The speed of the panzers enabled them to carry out vital reconnaissance, advance, defend, and attack vital or weak positions, after which the supporting infantry and artillery would hold the taken ground. While not meant for tank-against-tank action, these panzers were quite capable of luring enemy tanks into German anti-tank divisional attack. Supported by infantry and motorized divisions, these panzers could commonly be sustained in action logistically for three or four days of combat.

In 1940, the German Army was still two years away from possessing one of the most feared and best tank weapons of the Second World War, the Panzerkampfwagen Tiger. This heavy battle tank that mounted an impressive 88mm gun would engage in combat on all of Germany’s battle fronts and was truly formidable, weighing in at just under fifty-seven tons, with a speed of twenty-four mph, and two 7.92mm machine-guns with 4,800 rounds, as well as between ninety-two and 120 rounds for its main gun. But the Tiger was not available in 1940, and the Germans had no match for the heavy tanks of the French, which were well-armed and armoured. The Germans did, however, possess certain significant advantages over their opponents, not least being the new radios with which the panzers were all equipped, enabling vital voice communication with other units. Such communication made it possible for the German tanks to be immediately responsive in a constantly changing battlefield environment, making possible quick changes in tactics; easier, more fluid action than that of the enemy operating without the benefit of radio communication. The Germans strived to take full advantage of the radio communicating capability, considering it at least as important as accurate firing capability. Proper utilization of radio communication enabled tank commanders to coordinate their formations, assembling for mass firepower when the attacking or defending situation required it. Having the radio communication capability was a decided advantage in battle for the Germans.

Not only did the radio capability greatly enhance the tank-to-tank communication on the battlefield, it importantly put the tanks in touch with Luftwaffe units, either in the air or on the ground, so that vital air support could be requested and quickly provided in support of an attack or defensive situation. Such air support was normally provided by Ju 87 Stuka divebombers and it is believed that, for example, in Guderian’s famous dash to the Channel, his tanks never had to wait more than twenty minutes after calling the Luftwaffe for such support to arrive over the target area.

In the run-up to the offensive against the French, the German air force had 3,286 combat aircraft available in support of Army groups A and C, with 1,815 combat aircraft, 487 transport and fifty glider aircraft available in support of Army Group B. In 1940, the Luftwaffe, unlike the Wehrmacht, was operated without a central doctrine. Its facilities, equipment and personnel were then simply dedicated to the support of national strategy, including tactical and strategic bombing. More flexible in its usage, its applications included air superiority missions, strategic strikes, mediumrange interdiction, and close support of ground forces. In 1939, less than fifteen percent of the Luftwaffe resources were given over to support of the German Army.

Fall Gelb actually began on the evening of 9 May with the occupation of Luxembourg by German forces. During the night, German Army Group B started a feint into Belgium and the Netherlands and the next morning, Fallschirmjäger (paratroopers) of the 7th Flieger and the 22 Luftlande Infanteriedivision under the command of Generaloberst Kurt Student, a fighter ace of the First World War, appeared in a series of surprise landings on a road to Rotterdam, at The Hague, and on the Belgian fort at Eben-Emael in support of the advance of Army Group B. The German action was met by the French with their 1st Army Group sent north, and their 7th Army which crossed the Dutch border. The Dutch were in retreat and the French pulled back into Belgium to protect Brussels.

In the thrust into the Netherlands, the Germans took full advantage of their great numerical and qualitative superiority over the Dutch Air Force, destroying half the Dutch combat aircraft in the first day of the operation. The 144 combat aircraft with which the Dutch began that day were no match for the 247 medium bombers, 147 fighters, twelve seaplanes, and 424 Junkers Ju 52 transports that the Luftwaffe brought. In the 332 sorties flown by the Dutch, 110 of its aircraft were lost, for the loss of only a few German combat planes.

For German forces, the operation was initially a mixed bag. The 18th Army readily captured all the strategic bridges within and around Rotterdam, but an effort by the Luftwaffe to take the Dutch seat of government in The Hague did not succeed and resulted in considerable losses for the Germans. The taking of three vital airfields near The Hague, Valkenburg, Ockenburg, and Ypenburg, cost the Germans 125 of their Ju 52 transport planes destroyed and a further 47 damaged. Losses among the German paratroopers in the offensive were more than 4,000, roughly half their paratrooper force, of which 1,200 became prisoners of war. An additional ninety-six German combat aircraft were lost to Dutch shell fire. In the battle, forty-two percent of the German Air Force officers were lost.

On the ground, the reinforced 9th Panzer Division rolled into Rotterdam on 13 May, overcoming relatively light resistance by the French 7th Army. The Dutch attempted a small counter-offensive, the Battle of Grebbeberg, to halt and contain German progress there, but the effort failed and the Dutch forces retreated. The next day brought a heavy bombing raid on Rotterdam by the Luftwaffe, in which Heinkel He 111 medium bombers destroyed the central part of the city and the Dutch Army surrendered that evening, in an attempt to stem the German destruction of other Dutch cities. The Dutch Queen, Wilhelmina, arranged the establishment of a Dutch government in exile in Britain. The combined Dutch army, navy, air force, and civilian casualties in the German offensive totalled more than 4,900.

In dealing with Belgium, the Germans had done their reconnaissance homework and rather easily destroyed nearly half of the Belgian Air Force in the first day of operations there and by the end of that day, the Luftwaffe had secured air superiority over the region of the Low Countries.

But the main Allied strongpoint in Belgium was Eben-Emael, the large, modern fortress blocking the advance of the German 6th Army, whose feint offensive was stalling. Eben-Emael was located at the junction of the River Meuse and the Albert Canal, and the problem for the Germans was that a serious delay in their advance at that position threatened the outcome of the campaign. For the German Army Group A to establish bridgeheads in the area, it was vital that the main body of Allied forces there be engaged and to that end, the Germans decided on a new approach to assaulting the fort. Early in the morning of 10 May, some 230 German gliders landed near the site, delivering dozens of combat teams whose job was to disable the gun cupolas of the fort, using hollow charges. German paratroopers, meanwhile, were engaged in seizing the bridges over the canal. In the action, the Belgians counter-attacked, but their effort was halted by attacks from the Luftwaffe. The Belgian Supreme Command had planned, if necessary, a withdrawal to a pre-determined point, but were so shocked by the failure of their key fortification to withstand the German airborne assault, they ordered the withdrawal five days earlier than they had anticipated. The Dutch did manage to slow German progress some by blowing up most of the key river bridges, stalling the advance of the German armour briefly.

Prior to the Belgian defeat at Eben-Emael, the Allies had been counting on strong Belgian resistance to provide several weeks for their preparation of a new defensive line near the Gembloux Gap, between Wavre and Namur, an area of flat terrain, ideal for tanks.