Nazi Germany and the Soviet Union
In August 1939, as Europe slid towards another world war, Germany and the Soviet Union signed a non-aggression treaty. The Nazi-Soviet Pact came as a complete surprise to other nations, given the ideological differences between the two countries. It ushered in a period of military co-operation which allowed Hitler to ignore western diplomatic moves and invade Poland. Stalin's forces then attacked from the west and completed the subjugation and partition of the Polish state. For the next year and a half Germany also benefitted economically from the arrangement, with Russia exporting grain and oil in return for manufactured goods.
Soviet cooperation allowed Hitler to expand his plans for European domination. In May 1940 the Blitzkrieg rolled westwards and France was conquered in six weeks. But peace with Russia would not last. Hitler had always wanted to see Germany expand eastwards to gain Lebensraum or 'living space' for its people.
After the fall of France Hitler ordered plans to be drawn up for an invasion of the Soviet Union. He intended to destroy what he saw as Stalin's 'Jewish Bolshevist' regime and establish Nazi hegemony. The conquest and enslavement of the Soviet Union's racially 'inferior' Slavic populations would be part of a grand plan of 'Germanisation' and economic exploitation lasting well beyond the expected military victory. Regardless of recent economic and political co-operation, the Soviet Union was regarded as the natural enemy of Nazi Germany and a key strategic objective.
Operation 'Barbarossa'
On 18 December 1940 Hitler issued Führer Directive 21, an order for the invasion of the Soviet Union. The German military plan called for an advance up to a hypothetical line running from the port of Archangel in northern Russia to the port of Astrakhan on the Caspian Sea – the so-called 'A-A line'. This would bring the bulk of the Soviet population and its economic potential under German control.
After a five week delay while operations in Greece and Yugoslavia were completed, Operation 'Barbarossa' - named after the all-conquering Medieval Holy Roman Emperor Frederick I - was launched on 22 June 1941. Over three and a half million German and other Axis troops attacked along a 1,800-mile front. A total of 148 divisions - 80 per cent of the German Army - were committed to the enterprise. Seventeen panzer divisions, formed into four Panzer Groups, formed the vanguard with 3,400 tanks. They were supported by 2,700 aircraft of the Luftwaffe. It was the largest invasion force to date.
The German forces were split into three army groups, each with a specific objective. Army Group North was to head through the Baltic States of Latvia, Lithuania and Estonia and take Leningrad. Army Group South would attack into the Ukraine towards Kiev and the Donbas (Donets Basin) industrial region. Between them, Army Group Centre's objective was Minsk, Smolensk and then Moscow itself. Hitler expected these all to be attained in approximately ten weeks.
The Soviets had massed large forces on their western frontier, but they were under orders not to provoke the Germans. Although mistrustful of Hitler, Stalin did not believe that he would attack so soon, despite the ominous German build-up and a stream of intelligence warnings. He had some 5 million men available immediately and a total of 23,000 tanks, but the Red Army was still unprepared when the Germans struck.
The Germans got off to a good start, with the panzer groups quickly pushing towards their objectives and Russian forces falling apart in confusion. They were greatly helped by the Luftwaffe's bombing of Soviet airfields, artillery positions and troop concentrations. The Germans quickly established air superiority. On the first day alone 1,800 Soviet aircraft were destroyed, most of them on the ground. Army Group North, under Field Marshal Wilhelm Ritter von Leeb, plunged towards Leningrad, with General Erich Hoepner's Panzer Group 4 in the lead. Russian forces in this sector were thinly spread and the panzers covered 500 miles (804 km) in three weeks. By mid-July they were only 60 miles (96 km) from their objective.
Army Group Centre, under Field Marshal Fedor von Bock, also made rapid progress. By 28 June Panzer Group 2, led by General Heinz Guderian, and General Hermann Hoth's Panzer Group 3 had encircled three Russian armies and captured over 320,000 men in the Bialystok-Minsk pockets. The two panzer groups then pressed ahead, linking up on the far side of Smolensk on 27 July in another double envelopment. Two more Russian armies were trapped and destroyed, and another 300,000 troops taken prisoner.
Army Group South, under Field Marshal Gerd von Rundstedt, had the furthest to go and his attack also faced the stiffest Soviet resistance. Most of the Russian armour was on this front. But by early July von Rundstedt had pushed out beyond the pre-1939 Polish frontier. General Ewald von Kleist's Panzer Group 1 was slowed by Soviet flanking attacks as it headed for Kiev, the capital of Ukraine and key to the coal-rich Donets Basin. On 8 August the Germans surrounded two Soviet armies, capturing 100,000 men in the Uman pocket, and reached the Dnieper River. The naval port of Odessa on the Black Sea was also besieged.
Up to this point all seemed to be going well, the only major problem being the time needed for the infantry to catch up with the panzers and mop up pockets of Russian defence. But Soviet resistance was now stiffening, despite catastrophic losses. A German salient around Yelnya, south-east of Smolensk, was recaptured in a costly but successful counterattack.
Meanwhile, Army Group Centre's supply situation was becoming critical. Hitler decided to halt the advance on Moscow and reinforce Army Groups North and South. Hoth's Panzer Group 3 was sent north to support the drive on Leningrad while Guderian's tanks were despatched to help Army Group South take Kiev. The German High Command protested vigorously. The panzers were only 220 miles from Moscow. But Hitler regarded the resource-rich Ukraine as more important. On 21 August he ordered that the conquest of the Crimea and the Donets Basin be given priority.
The Soviets were completely fooled by German moves. Five Soviet armies were trapped in a vast salient around Kiev. As usual, Stalin refused to sanction a withdrawal before the pocket was sealed. By the end of September Kiev had fallen and over 650,000 Russian troops killed or captured. The Germans pushed along the Black Sea coast and into the Crimea, laying siege to Sevastapol. In October Kharkov fell, but by now the Germans were exhausted. The fighting had severely depleted their ranks and supply lines were stretched to the limit. For now, the southern front stayed where it was. In the north too, German forces had reached their limit. In September, with the aid of their Finnish Allies, they cut Leningrad off from the rest of Russia, but lacked the strength to take the city. Instead, Hitler ordered that it be starved into submission. The epic siege would last 890 days.
The battle for Moscow
Hitler now decided to resume the battle for Moscow. On 2 October he unleashed Operation 'Typhoon'. He believed the Russians had been fatally weakened and lacked the strength to defend their capital - one more push would see it fall and victory would be his. But the Red Army had been reinforced. Almost a million Soviet troops were in place, although they had few tanks and aircraft left. A multi-layered ring of defences had been thrown around the capital and its citizens had been mobilised. The German offensive was carried out by a reinforced Army Group Centre, comprising three infantry armies and three panzer groups - 1 million men and 1,700 tanks. However the Luftwaffe was weak after over three months of sustained operations. And the weather was beginning to turn.
Once again the initial assault was a success. The panzer divisions stormed ahead and over 600,000 Russian soldiers were captured in two more huge encirclements near the cities of Bryansk and Vyazma. The Russians were down to about 90,000 men. But as they reached the approaches to Moscow, the German formations slowed to a crawl. Autumn rains had turned the dirt roads into rivers of mud. It was the Rasputitsa - the 'quagmire season' - and wheeled and horse-drawn transport became hopelessly stuck. The Germans chose to temporarily halt operations.
In mid-November, with the temperature dropping and the ground now frozen hard, the panzers attempted a final pincer attack around Moscow itself. The delay had given the Soviets time to bring in further reinforcements, including reservists and troops from Siberia and the eastern borders. The northern German pincer was the most successful and got within 12 miles of the city. German officers could see the Kremlin buildings through their field glasses. The Germans also tried attacking in the centre, along the Minsk-Moscow road. On 2 December a reconnaissance unit got within 5 miles of Moscow. Though tantalisingly close, this was the limit of the entire advance. The depleted German units were exhausted and frozen into inactivity in the deep snow.
On 5 December the Soviets launched a surprise counter-offensive. The Germans were forced into a retreat, despite Hitler's call to defend every foot of ground. Guderian and several other senior generals who advised withdrawal were sacked. The Russians succeeded in crushing various German formations in encirclements of their own. The Luftwaffe struggled to operate but performed vital work ferrying supplies to cut off units and harrying the Russian advance. Army Group Centre was pushed back up to 150 miles from Moscow. A furious Hitler dismissed the commander-in-chief of the German Army, Field Marshal Walther von Brauchitsch, and appointed himself in his place.
Watch the invasion unfold
I this episode of IWM Stories, John Delaney tells the story of the invasion that changed the course of the Second World War.
On the 22nd of June 1941, Adolf Hitler launched Operation Barbarossa, Germany's invasion of the Soviet Union. It was the beginning of a campaign that would ultimately decide the Second World War.
At first, the Germans enjoyed stunning success, the panzers forged ahead, while the Luftwaffe ruled the skies. Hundreds of thousands of Russian soldiers were killed or captured in huge encirclement battles. Germany seemed to be on the brink of another major victory.
But the Soviet Union did not crumble as expected and despite terrible losses, their will to fight remained strong. German casualties mounted as they came agonizingly close to taking Moscow. Just 20 miles short of their objective, the Soviets launched a sudden counter-attack forcing the Germans onto the defensive. It was Hitler's first defeat on land in the second world war.
But how did it happen? Why did Operation Barbarossa come so close to success before falling at the final hurdle? Well, before we answer that question, a reminder to subscribe to the Imperial War Museum's YouTube channel for more videos just like this every two weeks.
Adolf Hitler begins planning to invade the Soviet Union as early as July 1940 before the Battle of Britain actually takes place. Even back in 'Mein Kampf' in the mid-1920s, he's planning to attack the Soviet Union. This is going to be the battleground on which National Socialism's ideology either wins out or flounders.
One of the tenets of that ideology was the idea of 'lebensraum or 'living space'. The creation of a Germanic Aryan Empire in Eastern Europe that would grant the resources needed for self-sufficiency. Having defeated France and the Low Countries in just six weeks, Germany was confident of capturing that land from the Soviet Union. Hitler believed that communist society was fundamentally weak and that it wouldn't take much to defeat it.
His famous quote is that 'all we've got to do is kick the door in and the whole edifice will come crumbling down'. The Germans are not only planning on a fast Blitzkrieg campaign that's going to knock the Soviet Union out of the war in six to eight weeks, but they need a fast victory. They can't have a slow attritional war because there's not enough reserves of men and material to turn this into a long war we need to win quickly.
To achieve that victory Germany mustered over three million men, the largest invasion force in the history of warfare to that point. Three army groups set out for three different targets, Army Group North heading for Leningrad, Army Group Centre aiming for Moscow, and Army Group South heading for Kyiv.
The whole strategy is a resumption of the Blitzkrieg idea that's been so successful in France, that is you win by not fighting. If you want to find out more about Blitzkrieg and how it works I've put a link to our video on the subject in the description.
When the operation commenced on the 22nd of June 1941 those tactics worked perfectly, the advance exceeding all expectations. Hundreds of thousands of troops were captured as German tanks steamed through the Soviet defences.
The Germans begin the campaign by basically destroying the Soviet Air Force on the ground, they catch them by surprise the Soviet Air Force is basically destroyed. Which enables the German army to move freely across the battlefield, thrust deep into the Russian interior and encircle the frontier armies.
The Soviet army was taken completely by surprise and had not had time to fortify their new border in Poland. While Stalin's purges of the Soviet Officer Corps left his army poorly led.
Whereas in the Battle of France the French and British armies would see themselves just about to get cut off and would decide 'oh time to retreat'. She Soviet armies are so slow, so badly led, that they don't have time to pull back. They get encircled completely cut off, hundreds of thousands of men. However, there is a problem.
By the time they reached this point Germany expected to have destroyed the Russian field armies and that the remaining surge towards Moscow would be more of a parade than a battle. But the Germans had completely underestimated the size of the Soviet army.
They're going to invade with about 3 million men and they expect the total Soviet army to be roughly the same. Whereas in actual fact by Christmas 1941, German armies have captured three million Soviet soldiers and they're still fighting.
Those vast distances covered by the German panzers made them more and more difficult to supply, while Soviet soldiers unexpectedly continued to fight.
So actually these big encirclements behind the German lines became a real problem in that they could now attack into the German lines of communication and cut them off from the front line. So at this point, Hitler said 'well hang on stop'.
Despite protests from the German generals, Army Group Center stopped its attack on Moscow and peeled off to the left and right to help destroy the Soviet pockets that were still fighting, killing or capturing hundreds of thousands more Soviet soldiers in huge battles of annihilation. By mid-September, the Soviet field armies were finally finished and the drive on Moscow could begin.
This pause to look behind and clear up behind, to allow everybody to catch up. It gives a breather for the Soviets to redefine their own front line and bring up more units into the front line dig in before Moscow. So there's now a completely new defence line that the Germans have to break through when they recommence the offensive.
And that wasn't the only problem for Germany. Though these new troops were undersupplied and under-trained, new supplies were beginning to arrive from Britain.
Many of these divisions don't have uniforms they're just civilian clothes, some of the divisions they have to share rifles there's not enough rifles to go around. At the same time, the first arctic convoys are arriving in Murmansk and Archangel bringing supplies from Britain, just giving enough equipment for the soviets to sort of stay in the field.
On top of that, the Soviets had managed to relocate their factories from in front of the advancing Germans to the Ural Mountains. That meant war production was actually kicking up and they were able to get more tanks like the new T-34 into the front line. Worst of all though was the rapidly deteriorating Russian weather.
Through October is the Soviet autumn. So what happens is you have snowfalls, thaw, snowfall, thaw, you get a completely muddy morass across all of central Russia. So the German offensive begins to grind to a halt both because they're coming up against this new defensive line that they didn't really expect. Plus the Soviet weather's getting in the way, plus the fact that now most German formations especially the armoured formations at the tip of the spear are now down to about 50 strength. They get to 20 kilometers away from Moscow and by that stage, the weather is now turned completely it's now full-blown Soviet winter. By the end of November, you've got more German troops in hospital with frostbite than you have with wounds.
The offensive was over, but looking at the whole picture as Barbarossa came to a halt Germany still seemed to be in a good position. Army Group North was sure that the besieged Leningrad was about to fall. Army Group Centre were at the gates of Moscow and Army Group South had taken the Ukraine and Kiev. When the new year came they planned to finish the job, however little did they know the Soviets had an ace up their sleeve.
They've managed to transfer the majority of those Russian divisions which were on the eastern side of the Soviet Union, those that had been facing Mongolia and the Japanese because they'd learned that the Japanese were not going to attack. These weren't green untrained troops, these were proper Soviet field divisions and many of them had been trained for winter warfare because they're from Siberia.
Unlike the exhausted Germans they would be facing, these troops had winter camouflage and weapons that could survive the extreme cold. On December 6th they counter-attacked.
And they launched this big Soviet counter-offensive in front of the gates of Moscow and catch the Germans completely by surprise and force them onto the retreat and that's the end of Barbarossa.
Hitler's ideological assumption that Soviet society would collapse when they kicked the door in could not have been further from the truth. The Germans needed a quick victory, but the Soviets had managed to stay in the fight and turn the Blitzkrieg Barbarossa into a war of production.
The Germans are now being forced into a war of attrition. A long, grinding, slow war in the Soviet interior, in this case in wintertime, and things are looking bad for the Germans because they haven't got the men and material to face up to the soviet armies on a one-to-one basis.
Despite Barbarossa's failure to finish the Soviets quickly, a new German offensive began in 1942. Under Hitler's direct orders the target was the Caucasus in the south and a city called Stalingrad. The German generals wanted to resume the push on Moscow, but Hitler insisted that Germany needed the oil fields in Azerbaijan to supply their armies. Though it escaped his generals Hitler had now realized this was a war of attrition and material whether he liked it or not.
Why Operation 'Barbarossa' failed
Operation 'Barbarossa' had clearly failed. Despite the serious losses inflicted on the Red Army and extensive territorial gains, the mission to completely destroy Soviet fighting power and force a capitulation was not achieved.
One of the most important reasons for this was poor strategic planning. The Germans had no satisfactory long-term plan for the invasion. They mistakenly assumed that the campaign would be a short one, and that the Soviets would give in after suffering the shock of massive initial defeats. Hitler had assured the High Command that 'We have only to kick in the front door and the whole rotten edifice will come tumbling down'. But Russia was not France. The shock value of the initial Blitzkrieg was dissipated by the vast distances, logistical difficulties and Soviet troop numbers, all of which caused attritional losses of German forces which could not be sustained.
The impact of Hitler's involvement
Hitler's input has been heavily criticised, not least by his generals at the time. Moscow was always a more important objective to the German High Command than it was to Hitler, who was more concerned with destroying Soviet field armies and capturing vital industrial resources. His switching of the main thrust from the central front to Leningrad in the north and Ukraine in the south was to an extent militarily sensible given the weakness of Army Group Centre after the Smolensk battles and the threats to its flanks. Indeed, the diversion actually worked in the Germans’ favour since it surprised the Soviets and resulted in the destruction of huge Soviet forces around Kiev. But it also threw away Germany's only real chance of outright victory.
The early capture of Moscow would have had an undeniable psychological impact and may have been the tipping point. Guderian in particular believed that using the panzers in traditional encirclement battles played into Russian hands and gave them chances to bring forward fresh reserves. He had advocated an all-out drive on the capital. But when Hitler resumed the assault with Operation 'Typhoon' it was too late. The German Army was now fatally weakened, the weather had worsened and Soviet reinforcements had arrived.
German Intelligence failures
German intelligence failures played a large part on several levels. The Red Army had been viewed with distain, especially because Stalin’s purges of the late 1930s had removed thousands of its officers - albeit temporarily in most cases. Its poor performance against the Finns in the winter of 1939-1940 also encouraged the Germans. Soviet industry was deemed incapable of producing modern weapons. Most importantly, Russian troop numbers and fighting strength were continually underestimated, so that despite the losses inflicted in early encirclement battles, the Germans always faced yet more reinforcements. The High Command had only considered the Soviet western army groups in their planning, and the presence of reserve forces and uncommitted formations in the Russian interior or on the eastern borders were disregarded. Even after Operation 'Typhoon' ground to a halt in early December, the Germans still chose to believe that the Soviets had nothing left to stage a counterattack.
Soviet tank superiority
While the Germans underestimated the military potential of their opponents, they also exaggerated the capabilities of their own forces, most significantly the four Panzer Groups. The panzer divisions were the principal weapon of Blitzkrieg and at that time were far superior to the Soviets in training, leadership and tactical ability. But they were relatively weak in numbers and equipment.
German tank strength had been halved in 1940 so that the number of divisions could be doubled. Over half the tanks committed to 'Barbarossa' were obsolescent light tanks and Czech-built models, rather than the more capable PzKpfw III and IV. And there were virtually no reserves available. Hitler had so far refused to fully mobilise the German economy and so weapons production was inadequate. Even in mid-1941 only 250 new tanks were being built each month, insufficient to properly equip the army on the eve of a major new campaign, or keep up with the inevitable mechanical and combat losses. Hitler even chose to divert some of these to France and other theatres, when the demand was greatest in Russia.
The vast majority of the 10,000 or so Russian tanks facing the Germans in June 1941 were light BT series tanks or obsolete T-26 models. Huge numbers were destroyed in poorly planned and executed counterattacks. But Soviet tank development and production was already superior to that of the Germans. A new generation of tanks had entered service, namely the T-34 and KV-1. The T-34 in particular was a major leap in tank design and came as a complete shock to the Germans when it was first encountered in July 1941. It had sloping armour - which effectively doubled its strength - and a powerful 76.2mm gun. Its reliable diesel engine gave it a good range and turn of speed, and its wide tracks could cope with mud or snow. Russian industry was already gearing up to turn it out in huge numbers.
Less than a thousand T-34s were available at the start of 'Barbarossa' and most were squandered in piecemeal actions by half-trained crews. But the Red Army could absorb significant losses of equipment as well as men. The mass mobilisation of Soviet industry had been set in train, which included relocating vital tank, aircraft and munitions factories eastwards to the Urals. This huge logistical undertaking was already bearing fruit. It meant that despite the early defeats, the Soviet Union was far better prepared for a long war than the Germans, whose own production of tanks and other weapons would be feeble by comparison.
German logistical problems
Logistics was another hugely important factor in the German defeat. No matter how fast or far the fighting formations advanced, they were dependent on timely supplies of fuel and ammunition. This became an ever greater problem as the army progressed deeper into Soviet territory and further away from its own railheads. Not only were the distances much greater than they had been during the French campaign, but the Soviet transport infrastructure was much poorer. German engineers struggled to convert the Russian railway gauge to one which their own locomotives and rolling stock could use. Meanwhile the multitude of lorries and horse-drawn wagons in which the supplies were transported were forced to negotiate Russian dirt roads, which became virtually impassable after prolonged rain.
The debilitating effects of the weather and terrain were not properly taken into account when planning the campaign. The numerous forests, marshes and rivers slowed the advance during the summer. The autumn Rasputitsa and the onset of the brutal Russian winter brought it to a halt during Operation 'Typhoon'. Tank and vehicle lubricants froze as temperatures plunged to record lows. Winter clothing supplies were held up in Poland, as fuel and ammunition took priority. If anything symbolises the failure of 'Barbarossa' it is the image of inadequately equipped German troops shivering in the snows before Moscow.
The success of Soviet resistance
Perhaps the most important reason of all for the defeat of Operation 'Barbarossa' was the tenacious resistance of the defenders. The Germans completely underestimated the Soviet will to fight. Hitler's announcement that the war in the east was one of 'annihilation' and Stalin's astute call to defend 'Mother Russia' rather than his own regime gave the ordinary Russian soldier - no matter how coerced or badly led - every reason to battle to the death. Hitler's infamous 'Commissar Order', which sanctioned the execution of all captured political officers, also stiffened Russian resolve. The Russian soldier was found to be a hardy and implacable foe, and quickly gained the respect of the majority of German front-line troops. No western enemy would come close to the Soviets in sheer staying power.
Despite the failure and huge losses of 'Barbarossa', Hitler launched another major strategic offensive in June 1942, this time towards the Caucasus mountains and the oil fields of Baku beyond. Morale was still generally high and German forces maintained the capacity to inflict further massive losses on badly handled Soviet formations. In fact 1942 would be an even worse year than 1941 for the Russians. But the factors that caused 'Barbarossa' to fail now conspired to doom this new enterprise as well. As the German columns advanced across the seemingly infinite spaces of the steppe towards their distant objectives, including a city named Stalingrad, the victory in the East that had once seemed so certain receded even further from sight.