Greetings! This is a fairly interesting question in that it touches ever so slightly on one of the key misconceptions of the Eastern Front (and World War II in general), that Nazi Germany invaded the Soviet Union during the winter. This could not be farther from the truth, as Unternehmen Barbarossa (Operation Barbarossa) was launched on June 22nd, 1941 In fact, Hitler agreed with his generals that the war against the Soviet Union was meant to be mostly concluded before winter, that is, the majority of key strategic objectives (Moscow, Leningrad, Stalingrad, and the Caucasus oilfields) were to have been captured before temperatures plummeted and the army would suffer from even greater attrition. However, as this response shall elaborate on a tad more, this sort of strategic thinking bottlenecked the German supply situation on the Eastern Front when it became clear that their campaigns in the USSR would not be over by winter 1941. Let's begin.

Note: parts of this response have been adapted from previous ones on the effectiveness of the Wehrmacht and the myth of invading Russia in winter.

Planning for the East

The origins of Hitler's campaign of conquest shifting from the West to the East resides in several factors. First we have the rhetoric he presented in Mein Kampf and built up in subsequent publications/speeches, the idea of lebensraum (living space) for the greater German volk (people). Even before the Battle of Britain had gone into full swing, Hitler was already considering what to do with the USSR. Of course, he had technically entered Germany into a non-aggression Pact with the Soviets (the Molotov-Ribbentrop Pact) and that technically meant that Germany could not declare war on the Soviets, but Hitler had always expressed a desire for something to come out of Russia, and that "something" is described rather well by Chant below:

"Russia must be dismembered so that the ‘Slavic sub-humans’ might be put in their correct place as underlings of the master-race, so that communism might be stamped out as a threat to national-socialism, and so that the German race might possess the necessary Lebensraum or living space in the east, together with its enormous potential in foodstuffs and industrial raw materials, not to mention oil. As always, this last item was well to the front of all Hitler’s thinking."

But Britain was proving to be a tougher nut to crack than Hitler and his general had foreseen. The Luftwaffe were bombing British airfields (and later towns) day after day, but the RAF continued their stubborn resistance against the stream of bombers that flew out across the Channel from airbases in German-occupied France. This comment again will not go too far into the course and eventual consequences of that Battle on its own, so I highly recommend cementing at least some foundational understanding of the Luftwaffe’s failures against the RAF.

For the purpose of this response, the key consequence is that the Battle of Britain brought the Soviet Union to the forefront of Hitler’s concerns regarding the course of the war. On the one hand, he could choose to maintain co-operative relations with the Soviets, who for their part were rather willing to fulfil German demands for food and minerals. On the other however, by 1940 Roosevelt had decided that American resources were best directed to defend British independence, which posed a new threat on the horizon to Hitler. If the Red Army could be destroyed in a single campaign and the Soviet resources brought under German control, the Third Reich could face the eventual Anglo-American alliance with greater confidence and attritional resistance. However, this all rested on the key assumption: if the Soviets could be taken out in one campaign.

To that end, Hitler approved the plans for Operation Barbarossa (red beard, after a highly respected Emperor of the Holy Roman Empire) on December 13th, 1940. Preparations were to be completed by May 15th, 1941 and the main plan envisioned three powerful thrusts. More on that in a moment, because we must first take into account the sheer scale of this venture.

In the Low Countries, the Wehrmacht had deployed some 91 divisions over a front of about 965 kilometers (600 miles), against the might of the Red Army, they deployed 146 divisions, along a front of 2092 kilometers (about 1,300 miles) in length. The Red Army divisions facing them in June 1941 totaled some 150 divisions, though most were understrength and the whole Soviet armed forces was still suffering from Stalin’s Purges.

The Red Army’s top brass had been absolutely decimated between 1938-39. In the Red Army alone, the purges had eliminated: 3 out of 5 marshals (among them the renowned Mikhail Tukhachevsky), 50 out of 57 corps commanders, and 154 out of 186 divisional commanders. A new batch of officers and generals was being trained, but these men would take time to grasp the intricacies of mechanized warfare.

Barbarossa was formed of a three-pronged thrust into the Soviet heartlands, striking at key cities such as Leningrad, Moscow, and Kiev, as well as seizing the Caucasus oilfields in the south. The first target was entrusted to generalfeldmarschall Wilhelm Ritter von Leeb’s Heeresgruppe Nord (Army Group North), formed of six mobile and twenty-three infantry divisions. Kiev was entrusted to generalfeldmarschall Gerd von Rundstedt’s Heeresgruppe Sud (Army Group South), formed of eight mobile and thirty-three infantry divisions (among them some Romanian divisions). The prize of the Soviet capital however, fell to generalfeldmarschall Fedor von Bock’s Heeresgruppe Mitte (Army Group Centre), formed of fifteen mobile divisions and thirty five infantry divisions. Among the troops under Bock’s command were the 2nd and 3rd Panzergruppen of Erich von Manstein and Hermann Hoth, two of the most battle-hardened and well-equipped contingents in the entire force. The general tactics were similar to those which had worked so well in the West: mass encirclements of Soviet forces enabling swift strikes towards key points. However, the critical factor here, was supply. The encirclements were planned to take place as close as possible to the Western border as possible, enabling the resupply and reinforcement of the various army groups to sustain the campaign. It was this critical factor which soon shot the bolt of the entire Russian campaign.

On June 22nd, after a crucial month’s delay at Hitler’s insistence to deal with Yugoslavia and Greece, the operation was launched. In the first few weeks, all three Army Groups made spectacular progress. By July 13th, some 4 million Red Army troops had been killed, wounded, or captured. The Wehrmacht had pushed the borders of the Third Reich as much as 800 kilometers (600 miles) further. Massive encirclements of hundreds of thousands of troops had taken place around Bialystok, Minsk, Kiev, Kharkov, and Vyazma (not including the countless smaller encirclements of sub-division formations). Chief of staff general Franz Halder remarked in his diary on July 3rd:

“It is thus [in light of the success of the invasion] probably no overstatement to say that the Russian Campaign has been won in the space of two weeks. [However], the sheer geographical vastness of the country and the stubbornness of the resistance, which is carried on with all means, will claim our efforts for many more weeks to come.”

As if fulfilling Halder’s insightful assessment, two forces then interfered, both with devastating consequences.

Part 1 of 2