New plans had to be made, as Russia was stronger than thought

By 28 August 1941, the Germans realized that they were likely not to achieve their objects before winter, and they needed to make longer term plans about the course of the campaign in Russia. They faced the reality that the British would be in contact with Russia through Iran. In the Middle East, the British seemed to be too weak to launch an attack, but if Rommel were able to take Tobruk, that might help the Axis supply situation. The British goal would obviously be to expel Axis forces from North Africa, and that would allow the Americans free access to French North Africa and West Africa. This is based on the account in Vol.II of the Official History.