There were several reason why eventually Op Barbarossa failed,but none of them would in either way cloud the fact that the operation itself was essential and quite well thoughtout.In letter written to Mussolini,Hitlers expresses his thought of concern on the eastern front.Hitler is worried that the soviets are going to open up the eastern front and the evidence was the massing of soviet forces on the 1000 mile long eastern front with Germany and German occupied Baltic and Balkans.considering the surprise by which Barbarossa took the soviets,this must have been defensive posturing,as the soviets also claimed with the Germans.
Whatever the act,Hitler was determined to take out the soviets from the equation when the going was good.he also thought that with USSR gone,Great Britain would agree to surrender or come to a compromise over the future of Europe and bring the war to an end.
If we go into the details of the largest battle operation in the world war II(a record unbroken before or after the war),it was doomed from the beginning.OKW(German army HQ)had extensive studied the every battle that had been waged giant Russia,including Napoleon's disastrous 1812 campaign and they had devised a three pronged attack on the USSR.In the north pushing towards Leningrad was Gen Leeb's Army group North and in the south pushing towards Stalingrad,through Ukraine was the army group south.However the best and largest battlegroup was the army group center making headway to Moscow the soviet capital.
The operation supposed to unfold in the early days of march-april 1941,this was calculated to give the Wehrmacht enough time to drive towards the Moscow,Leningrad(St Petersburg) and Stalingrad,before the onset of the Russian winter in November-December.However fate had it otherways.Much against his advise Italian dictator Mussolini made an ill advised move against neutral Greece and took a heavy beating.with the Greeks threatening Italian controlled Albania and opening up the southern flank.Germany had to come to aide of the bungling Italians.Its was only in April of 1941 that Hitlers army could break the Greek defense and occupy Greece.This diversion forced Hitler to postpone Barbarossa to may and later June and the in the hindsight,three to four months were wasted on the Greek front when he could have been heading to Moscow........This, as later events would transpire,prove costly for the Germans.
Even though he had to delay Op Barbarossa by several months,thanks to his Russian blitzkrieg Hitler could still have managed to push into Russia proper and Moscow before the winters.The original plan was the take Leningrad in the north and join with the German forces in Finland,push towards Ukraine and capture Stalingrad and occupy the caucusus,with the northmen and southern flank covered the army group center could then make the push towards Moscow,where Soviet union had assembled its best fighting force under Marshall Tomishenko .However during the initial days the Wehrmacht,in the manner of the same Blitz that had conquered France,had pushed deep into soviet territories and had captured the strategically important city of Smolensk,just 200 miles away from Moscow(this was in July)
This Blitzkrieg called for a change in plan,with the best Russian forces digging in to face the massive German army group center,Gen Von Bock,commander of the army group center wanted to continue all the way to the soviet capital.Hitler disagree and wanted to wait until his forces had occupied Leningrad in the north and army group south had captured Stalingrad.Nothing could persuade Hitler that with the fall of the Moscow,with the loss of leadership and communication,the defenses in Leningrad and Stalingrad would automatically collapse.
Eventually with the Russians giving tough resistance in the south,esp at Stalingrad,Germany had to pull out panzer divisions from the army group center move them to the Crimea for reinforcement.While the Crimean occupation was successful,Germany too suffered heavily(in Stalingrad).the strength of his panzer division,which were later sent to the army group center,was greatly diminished and were in severe need for repairs.
Eventually when Hitler gave orders for the Moscow push,its was already October and USSR was under heavy snowfall and rainfall,as a result the slushy terrain greatly impeded the German march towards Moscow.because the German forces had moved so far away from German soil,it was impossible to give them proper air cover(most German airfields were still in Germany and western/eastern Europe)and they came under heavy pressure from the soviet air force.
German forces never made it to Moscow and even their victories in Leningrad and Stalingrad came at heavy cost,which tilted the military balance against the Germans.Germans could never consolidate their gains and they couldn't cripple the soviet leadership and communication.
In the Napoleonic wars,the Czar's army never gave the french a chance to wage a decisive battle against the inferior Russians.the French kept going after the Russian hoping to finish them and eventually had to retreat due to bad weather conditions and because they were unable to pursue the Russian any further.Hitlers forces had the Russian in their sight and Russians could not retreat faster than the German blitz,but they lost plot when it mattered and failed to inflict a decisive blow to the bulk of the soviet forces which was defending Moscow.
