World War I proved that the machine gun, supported by artillery, can stop whole armies on its tracks and positional warfare leads to a costly stalemate. The huge difficulty in breaking the defensive line was not the only problem. Even when the line was breached the defending army could swiftly transport its reserves to the sector where the rupture had occurred since this movement, behind the front, could proceed free of enemy interference. Once in position, these reserves could either launch a counterstroke to regain the lost positions or establish a new defense line a few miles behind the original one. Defense reigned supreme.

Left. The machine-gun could stop almost any attack during WW 1. Right. Even if a defense line had been breached, reinforcements moving behind the front could pour in to seal the gap, unhindered by the enemy.

To avoid a repetition of these pointless battles, European military theorists searched for ways to pierce these strong defensive lines with new tactics, like infiltration, and new weapons, like the tank.

Eventually, tactical concepts developed into operational doctrines. Russian, British and German armies of the mid-‘30s arrived at a solution whose approach was, on paper, remarkably similar. The common idea comprised a method of attack using the tank as the main weapon to breach the defenses followed by the rapid penetration of the enemy lines in great depth using motorized troops.

The German and Soviet armies became very offensive-oriented with the adoption of this formula and both invested heavily to make it work . However, the Germans were much more successful in practice. The name Blitzkrieg used to christen this doctrine, emerged after the first dramatic success in Poland in 1939.

Its effectiveness came as a shock not only to the enemy but also to many German army conservative thinkers who initially were against it. German generals Heinz Guderian (Heer) and Walther Wever (Luftwaffe) , the main exponents, were right, as was Hitler, who supported them.

The blitzkrieg is a method to conduct and win the air-land battle using combined-arms teams of aircraft, tanks, mechanized troops, and infantry. Tank equipped formations break the defensive line, followed by armored and motorized troops that penetrate rapidly thorough the gap in great depth, preventing the slow-moving enemy army from establishing a new defensive line in the rear. Simultaneously friendly aircraft pounce on these enemy’s reserves during their movement along roads and railroads to interdict their advance.

By keeping the offensive from the first day to the last of the hostilities, the defender would lose its freedom of action while the attacking army would retain the strategic initiative until victory was on its hands .

The approach is bottom-up. Defeating enemy soldiers similarly armed is a hazardous enterprise. Destroying every enemy formation directly implies substantial losses and these operations are time-consuming. Imagine that a group of 10 well-armed men appear in your neighborhood to rob a bank. Even if a powerful SWAT team deploys to neutralize them you can realize that it will not be an easy task: it will take time and blood to do it. If this is multiplied a hundred times, you can start to see the difficulty.

On the other hand, every soldier, tank, or artillery gun has a weakness that renders them impotent: their finite capacity to carry with them ammo, fuel, and food.

This hauling capacity is very low: an infantry soldier could carry some 30 kg (60 lbs.) of gear, that included weapons, helmet, gas mask, food, ammo, and other equipment. The German infantryman armed with a rifle or carbine had 2 cartridge pouches (each with 3 pockets) with a total capacity of 60 rounds and a bread bag with one or two rations. This translates into enough food for one or two days and ammunition for an intense battle lasting an hour or two at the most.

A German Panzer III Ausf. H tank had enough fuel for 160 km on the road (320 liters) and 99 projectiles for the main 50mm gun, plus 2700 rounds of ammo for the machine gun . Enough for a two-day advance and around two or three intense fire engagements .

Once a soldier uses up its ammunition, its status changes from a ferocious warrior to a uniformed civilian. A tank without fuel and ammo becomes just a heavy immobile vehicle by a roadside .

This low-carrying capacity requires a logistics system to keep the armed forces supplied using a conveyor-belt type operation. An unsupplied army can only flee or surrender. How can the fighting continue if the troops do not have the means to defend themselves?

Encircled troops do not surrender because they become disheartened. They surrender when they exhaust their supplies. To the layman, it may appear strange why so many soldiers surrender instead of fighting to the death. In practice, the reason is that the ammunition stocks ended before the will to fight.

Preventing the enemy from resupplying its troops is then an effective way to eliminate large enemy formations quickly and at a lower cost. But how to do this? The fundamental principle of the blitzkrieg was to encircle and destroy the adversary. To do that, the Germans deployed tanks to breach the enemy defensive line at tactical depth to achieve a breakthrough (durchbruch) . Tanks have armor plate and are impervious to machine-gun fire, so they can move over terrain defended by light forces armed with small arms . The Germans used tanks en masse to saturate the defenders and overwhelm the few anti-tank guns present in the attacked sector, carefully selected beforehand by reconnaissance troops precisely for this reason. After a successful breakthrough, additional mobile troops penetrated deeply through the breach towards the enemy rear, bypassing pockets of resistance in a maneuver called exploitation, obstructing any enemy’s supply columns encountered. The mobile troops continued their advance until the encirclement of the opponent was complete, thus foiling its resupply for good.

Friendly infantry penetrated through the gap and marching on foot on the wake of the mobile troops arrived to consolidate the encircling ring preventing an enemy break-out. Lastly, the infantry battalions forced the encircled enemy to do battle and fire, causing it to spend its ammunition and surrender .

Infantry column penetrating through the gap
Panzer troops on the move.

This deep penetration, however, creates a serious vulnerability problem. Troops on the march are much more exposed than troops deployed in static, well-entrenched defensive positions. They are also more visible, presenting an easier target: the columns of dust generated by motorized columns on the move are conspicuous from many miles and can attract artillery fire like a magnet. At the same time, the large magnitude of the penetration means that troop density is sparse. A Panzer division advancing is a thin column 110 km (70 miles) long. However, by design, a divisional-sized unit can defend a sector 10 km (6 miles) wide or fight a delaying action over a 20 km (12 miles) frontage . Troop density is therefore, too thin to protect an exposed flank of this magnitude unless the advancing troops have time to concentrate to defend a specific sector.

An enemy counterattack mounted by his reserves against the flank of advancing mobile forces can be devastating. It can overrun the encircling units and dislodge their supply. Legend has it that panzer leaders had nerves of steel and disregarded their flanks. This is a half-truth.

The use of a tactical air-force helped to solve this problem and by design, it was an indispensable part of the combined-arms, Blitzkrieg concept . The Luftwaffe had 4 main missions to play within this doctrine :

First and most important was the attainment of air superiority. The German bombers started to bomb enemy airfields right at the outset to destroy enemy aircraft on the ground and their supporting infrastructure (maintenance hangars, fuel and ammo depots, and command centers). Fighters would fly aggressive hunting missions over enemy territory to shoot down any enemy aircraft that attempted to respond. The aim was to gain control of the volume of airspace above the friendly mobile troops and some distance beyond creating a large bubble where the German aircraft could execute their missions and the enemy aircraft could not. Fighters played the most decisive role in this mission.

With the achievement of air superiority, reconnaissance aircraft flying ahead of the mobile divisions identified enemy troops deploying defensively or offensively and military units moving rearward or forward. This aerial mission by itself reduced dramatically the threat on the German mechanized formations because it provided them the initiative, affording the panzer leaders the confidence to move forward knowing that their flanks were under vigilance.

Stuka dive bombers en route to strike a target
Soviet airfield after a Luftwaffe attack

The nature of this observation mission is analogous to the use of radar by the British during the Battle of Britain: radar allowed the RAF to detect attacking Luftwaffe formations and use Fighter Command squadrons only at the points of their choosing. Radar was unsuitable to detect enemy units on the ground, but the human eye and photographic cameras are effective sensors. Air-reconnaissance squadrons scanned broad sectors around the advancing panzer divisions, detecting attacking enemy formations and disseminated vital information to the appropriate commands. This crucial intelligence allowed the friendly mobile forces to set up defensively with enough time in case of a hostile counterattack, concentrating strength opposite the enemy axis of advance. Simultaneously, the armored combat groups (Kampfgruppen) could carry out spoiling attacks on the flanks of the enemy counterattacking units while they were on the march, (when they were most vulnerable), forcing them to abandon their assault . Like in the skies over Britain, small formations (in this case mobile troops) concentrated in space and time could act decisively.

War games reveal that the side that can identify the type, size, placement, and direction of movement of enemy’s formations (i.e. “armored brigade outside of Brest moving westward”) has an enormous advantage over the side that does not have this intelligence . Air superiority allows friendly aircraft to observe and inform on the enemy’s intentions, while it turns the enemy blind.

Third, Luftwaffe bombers attacked the enemy troops located by the recce aircraft to reduce the speed of movement and degrade their capabilities. They also bombed command post to hinder coordination efforts and communication networks (cities, roads, and railroads), selecting specific infrastructure bottlenecks (i.e. bridges, rail junctions, entrance and exits of cities), whose destruction prevented or reduced enemy’s reinforcement and resupply capabilities. The Luftwaffe did not have enough bombers to obliterate large enemy fighting groupings (i.e. brigades or higher), but it had adequate strength to create holdups to enemy movement, securing time for the German mobile forces. Aerial strike forces were also strong enough to impair significantly the supply condition of enemy formations making them brittle. Contrary to widespread belief, the horizontal and dive bombers dedicated more effort to interdiction in the rear zone than to striking enemy troops in the battle area. There is a very good reason for this. In the battle area, the deployed enemy companies scatter and entrench on their sectors to minimize detection and to reduce casualties in case of a hit. Aerial bombing is most effective against clearly defined targets that are relatively stationary, of appropriate size, and compact, conditions that are hard to find in the battle zone. Furthermore, most of the enemy anti-air defenses are precisely in the battle area, increasing bomber losses. On the other hand, it is easier to destroy fuel and ammunition trucks traveling in long exposed columns on roads or on freight trains and it is just as effective: a tank becomes impotent by lack of supplies even if it remains undamaged.

In comparison, the aerial attack of enemy ground troops opposing the advance of armored formations played a secondary role. The use of Luftwaffe aircraft as aerial artillery , very often mentioned by several authors as the key role of the German air force, only played an important part when the war of movement was starting or when it was momentarily on hold. When these conditions were prevalent, the bomber wings would strike the enemy defending prepared or fortified defenses that were easily identifiable from the air (for example, across a river, in a town or forest). Even in those instances, however, the sorties dedicated to this form of attack were relatively small. Given the tremendous frontage of the eastern front, ground troops proved consistently able to find suitable weak spots on the enemy defense to perforate it without the support of strike aircraft .

Only air superiority permitted the bomber force to roam at will, whereas without it, the enemy strike force would suffer devastating losses attempting to destroy the juicy targets on the roads.

Stuka destroying a Russian pontoon bridge. Without both bridges, Russians could not supply their troops
Messerschmitt Bf 109E over Smolensk in a free hunt to maintain air supremacy. Although by this stage most of the Bf 109 in Russia were Fs, a few Gruppen soldiered on with Es.

The last aerial mission that the Luftwaffe executed during the blitzkrieg was logistic support by transport aircraft. The logistics of a fast-moving army are daunting, and crises occur frequently. Supplies delivered by air to the forward troops (spearheads) strengthen the capabilities of the supply system allowing the war of movement to maintain momentum .

Thus, the German air force’s main effort focused on supporting the exploitation, not in achieving the breakthrough.

Luftwaffe’s support for large ground offensives proved decisive. No German large-scale offensive ultimately succeeded in any front during the war unless under conditions of friendly air superiority. Similarly, the Russians found nearly impossible to sustain deep ground advances while under air inferiority conditions, unless they attacked protected by harsh weather that hindered air operations or by spreading their attacks along the whole front to prevent the German air force to concentrate against a single all-important assault.

The importance of the Luftwaffe in the large expanses of the Russian hinterland was even more vital than in more restricted theaters of war because counterstrokes could come from any unobserved place. Therefore, the German air force concentrated all its available strength in decisive axes of advance or sectors, while the rest of the German ground formations received limited support (reconnaissance and some air protection).

The concentrated support applied not only to the Luftwaffe aircraft but also to the independent Luftwaffe ground antiaircraft artillery battalions organized in Flak corps. These light (20mm) and heavy (88mm) battalions provided an additional protection layer to the armored and motorized divisions which already included an organic self-propelled or motorized AA Flak company (respectively).

Upon completing a successful encircling operation, another would start , making it very difficult for the enemy to establish a new strong line of resistance. However, reserves in great depth are a good defensive strategy against a Blitzkrieg offensive because penetrations deeper than 300km were very difficult to achieve in one swoop.

The Blitzkrieg offensive mechanism may appear like an irresistible formula to win the battle, but in practice, it is enormously complex to implement. Marshal Mikhail Tukhachevsky in Russia, with the full support of Stalin, attempted to do the same thing, even adding large paratroop forces to the recipe, but he failed. This may have cost him his life .

To make it work the Germans solved many teething real-world problems both in the ground and in the air:

They created from scratch, armored divisions organized such that all the arms: infantry, artillery, tanks, and supporting troops (engineers, recce, flak, anti-tank, signals, etc.) could move at the same pace .

They designed new equipment for these mobile troops and developed specialized training, so they could execute their missions with proficiency. The Germans also created a command organization able to receive real-time information from multiple air and land sources; process this information to create a picture of the situation; trained officers to make right decisions quickly and developed communication systems to disseminate the orders so they could reach the required troops on the move on time .

Highly aggressive and mobile reconnaissance troops moving ahead of the main body were available to identify suitable terrain and the strength of enemy defenses. With this information, divisional commanders redirected the movement of battle groups to maintain the momentum of advance.

The German leaders also developed a tactical air arm able to carry out the 4 missions outlined previously and supported it with a ground organization that allowed operations from recently captured airfields with minimal delay.

A sufficiently large defense-industrial complex and training organization that permitted the deployment of enough force to break defenses, attack en masse and protect themselves while moving underpinned the whole effort .

Finally, they established a supply and maintenance organization that allowed the armies to keep moving and fighting. This problem was a major nightmare because delivering immense quantities of material to troops that are far from the supply centers and changing positions every day is an enormous task. On-the-field maintenance, evacuation, and repair of heavy vehicles is another major difficulty that the Germans solved. A description of the German logistics will follow later in the chapter given its importance.

The German army developed and implemented the Blitzkrieg operational doctrine splendidly . After successive improvements prompted by multiple real-life exercises and the experience of battle, the Germans transformed it into a ruthlessly effective method to carry out and win the air-land battle .

Blitzkrieg Air-Land Mission Table. Air missions in blue, land missions in green.


Initial Situation and Deployment

The Enemy MLR (Main Line of Resistance) is the red thick line. The defender is supplying its troops through the railroad that drops stores at the railhead (1) and thence to the depot (2) by road. Lower echelon transport then delivers the supplies to the troops (3). Enemy tactical reserves, deployed some distance from the MLR, are ready to plug any holes if necessary (4). Operational reserves, kept well behind the front, are available to the defending commander to counterattack and force the attacker to withdraw (5). The defender air force occupies the airfields to the east of the MLR (6). The Germans have deployed fighters (7) and bombers (8) to airfields close to the front and within striking distance of enemy airstrips. Infantry formations occupy positions along the MLR while the main attacking forces, formed by armored units supported by infantry elements deploy, using high-unit density, over suitable terrain (9). Finally, the Germans place their reserves near the expected breakthrough points (10), ready to exploit and to widen the breach.

Breakthrough Phase

Luftwaffe bombers attack enemy airfields (1) while fighters shoot down any enemy plane that attempts to intervene (2), creating a 3D bubble of air superiority over the battlefield (3). Simultaneously, mixed infantry and armor battlegroups attack the weak spots on the enemy defense complex piercing the line of defense at tactical depth and therefore, achieve breakthroughs at two points (4). Bombers support one of the attacks directly to wreck enemy fortified defenses (5). Infantry and armored reserves behind the breakthrough locations prepare to move forward (6).

Exploitation Phase

The armored battlegroups push forward through the breach severing the railroad at two points (1). Infantry follows behind as fast as possible (2). Other infantry units pin the enemy troops in the original MLR to prevent their withdrawal (3). Observation aircraft carry out intense reconnaissance to detect any movement or threat ahead and in the flanks of the advancing armored units (4). German bombers isolate the battlefield by destroying identified hostile supply columns preventing enemy resupply (5) and any identified enemy units attempting to counterattack or to withdraw (6). Reconnaissance aircraft reports flow to the appropriate ground commands who deploy troops in the exposed sectors (7) while fighters continue aggressive hunting preventing the enemy air force from carrying out its missions (8).

Encirclement and Mop-up Phase

Armored troops close the pincers encircling a considerable number of enemy troops (1). Infantry following behind consolidates the pocket, preventing enemy elements to escape. Then, they start attacking the surrounded troops to force them to fire and consume their ammunition (2). With the supplies gone, the enemy surrenders and the Germans grasp the fruits of the attack.
German aircraft move to bases farther ahead (3) to continue intense observation, maintain air superiority and attack threatening columns thus allowing the elimination of the isolated pockets (4). Once the destruction of the pockets is complete, a new operation starts.