In spite of the Molotov–Ribbentrop Pact, signed in 1939, Nazi Germany began Operation Barbarossa—the invasion of the Soviet Union—on 22 June 1941.
Initially the Luftwaffe was at an advantage, destroying thousands of Soviet aircraft in the first month of fighting.
Hitler and his top staff were sure that the campaign would be over by Christmas, and no provisions were made for reserves of men or equipment.
But, by July, the Germans had only 1,000 planes remaining in operation, and their troop losses were over 213,000 men.
The choice was made to concentrate the attack on only one part of the vast front; efforts would be directed at capturing Moscow.
After the long, but successful, Battle of Smolensk, Hitler ordered Army Group Centre to halt its advance to Moscow and temporarily diverted its Panzer groups north and south to aid in the encirclement of Leningrad and Kiev.
The pause provided the Red Army with an opportunity to mobilize fresh reserves; historian Russel Stolfi considers it to be one of the major factors that caused the failure of the Moscow offensive, which was resumed in October 1941 with the Battle of Moscow.
Poor weather conditions, fuel shortages, a delay in building aircraft bases in Eastern Europe, and overstretched supply lines were also factors.
Hitler did not give permission for even a partial retreat until mid-January 1942; by this time the losses were comparable to those of the French invasion of Russia in 1812.

Hitler decided that the summer 1942 campaign would be concentrated in the south; efforts would be made to capture the oilfields in the Caucasus.
The Battle of Stalingrad, a major turning point of the war, began on 23 August 1942 with a bombing campaign by the Luftwaffe.
The German Sixth Army entered the city, but because of its location on the front line, it was still possible for the Soviets to encircle and trap it there without reinforcements or supplies.
When the Sixth Army was surrounded by the end of November in Operation Uranus, Göring promised that the Luftwaffe would be able to deliver a minimum of 300 tons of supplies to the trapped men every day.
On the basis of these assurances, Hitler demanded that there be no retreat; they were to fight to the last man.
Though some airlifts were able to get through, the amount of supplies delivered never exceeded 120 tons per day.
The remnants of the Sixth Army—some 91,000 men out of an army of 285,000—surrendered in early February 1943; only 5,000 of these captives survived the Russian prisoner of war camps to see Germany again.
In spite of the Molotov–Ribbentrop Pact, signed in 1939, Nazi Germany began Operation Barbarossa—the invasion of the Soviet Union—on 22 June 1941. Initially the Luftwaffe was at an advantage, destroying thousands of Soviet aircraft in the first month of fighting. Hitler and his top staff were sure that the campaign would be over by Christmas, and no provisions were made for reserves of men or equipment. But, by July, the Germans had only 1,000 planes remaining in operation, and their troop losses were over 213,000 men. The choice was made to concentrate the attack on only one part of the vast front; efforts would be directed at capturing Moscow. After the long, but successful, Battle of Smolensk, Hitler ordered Army Group Centre to halt its advance to Moscow and temporarily diverted its Panzer groups north and south to aid in the encirclement of Leningrad and Kiev. The pause provided the Red Army with an opportunity to mobilize fresh reserves; historian Russel Stolfi considers it to be one of the major factors that caused the failure of the Moscow offensive, which was resumed in October 1941 with the Battle of Moscow. Poor weather conditions, fuel shortages, a delay in building aircraft bases in Eastern Europe, and overstretched supply lines were also factors. Hitler did not give permission for even a partial retreat until mid-January 1942; by this time the losses were comparable to those of the French invasion of Russia in 1812.
Hitler decided that the summer 1942 campaign would be concentrated in the south; efforts would be made to capture the oilfields in the Caucasus. The Battle of Stalingrad, a major turning point of the war, began on 23 August 1942 with a bombing campaign by the Luftwaffe. The German Sixth Army entered the city, but because of its location on the front line, it was still possible for the Soviets to encircle and trap it there without reinforcements or supplies. When the Sixth Army was surrounded by the end of November in Operation Uranus, Göring promised that the Luftwaffe would be able to deliver a minimum of 300 tons of supplies to the trapped men every day. On the basis of these assurances, Hitler demanded that there be no retreat; they were to fight to the last man. Though some airlifts were able to get through, the amount of supplies delivered never exceeded 120 tons per day. The remnants of the Sixth Army—some 91,000 men out of an army of 285,000—surrendered in early February 1943; only 5,000 of these captives survived the Russian prisoner of war camps to see Germany again.
Hermann Göring