Background to Operation Barbarossa

By the Summer of 1940, Germany had defeated France, driven the British army out of continental Europe, and occupied France, Belgium, Luxembourg, the Netherlands, Denmark, and Norway, as well as continuing to hold its previous conquests of Poland, Austria, and Czechoslovakia. Hitler visited Paris for a lightning tour, immediately after the defeat of France, and the successful conclusion of the land campaign in Western Europe. However the war in the West was not over at this point: Britain still remained undefeated The Battle of Britain had not yet occurred Hitler had not yet even ordered a possible invasion of England (Hitler ordered preparations for Operation Sealion only on July 16th in War Directive 16) Even so, Hitler seems to have already begun considering an attack on the USSR, an idea that he had first contemplated as long as a go as the 1920s, and which he had described in his 1925 book, Mein Kampf. It is possible that Hitler at first believed that Britain would soon come to terms without invasion, but surely such an impression could not have lasted. Hitler sometimes told others, that the attack on the Soviet Union would lead to the defeat of England - since it would deprive the country of its last possible continental ally, strengthen Germany (through the conquest of economic and industrial resources), and strengthen Japan's position in the Far East, making US intervention in Europe less likely. However, it can not be denied that Hitler had long held a goal of conquering vast territories from the USSR, and then attempted to pursue this goal as soon as the opportunity arose - even when doing so meant that Germany would become involved in a two-front war.

As early as July 1940, immediately after the defeat of France, Hitler began considering the possibility of attacking the USSR. Hitler received military plans for an invasion of the USSR on December 5th 1940, and then signed War Directive No. 21 on December 18th 1940. The text of the Directive stated among other things: "The German Wehrmact (Armed Forces) must be prepared, even before the conclusion of the war against England, to crush the USSR in a rapid campaign (Operation Barbarossa)." "Preparations which require more time than this will be put in hand now, in so far as this has not already been done, and will be concluded by 15th May 1941." "It is of decisive importance that our intention to attack should not be known." "The bulk of the Russian Army stationed in Western Russia will be destroyed by daring operations led by deeply penetrating armoured spearheads. Russian forces still capable of giving battle will be prevented from withdrawing into the depths of Russia." "The enemy will then be energetically pursued and a line will be reached from which the Russian Air Force can no longer attack German territory. The final objective of the operation is to erect a barrier against Asiatic Russia on the general line Volga-Archangel.". While Directive 21 did not irrevocably set Germany on a path to attack the USSR, it did contain a tentative start date to the campaign of May 15th 1941.

1. The build-up of forces took longer than expected.
   
   
2. Some German forces were diverted to attack Yugoslavia (which had been about join the Axis, but the experienced a pro-British military coup), and Greece (which the Italians had been fighting unsuccessfully since the previous year).
   
   
3. The Spring rains came to European Russia later than expected. The rain turned the ground into virtually impassable mud.