Was British prestige really a valid reason for sending troops and equipment into Greece? The Australian General Blamey thought that the chance of success was low and that a defeat would do more harm to British prestige than the gesture of sending a force. Churchill and Anthony Eden seemed to think that there was a real chance of Yugoslavia and Turkey joining in the fight in a meaningful way. In fact, Turkey was better off staying neutral, because the British strength was so inadequate for the task of opening up a Balkan front. Generals Wavell and Wilson's opinion didn't count, as they were essentially "yes-men" for Churchill. As we have said, the primary result was to write off a sizable portion of the Royal Navy in the combination of Greek campaign and the battle for the island of Crete.
The Germans were able to deploy a large force for the Balkans, since the attack on Russia was postponed. The Official History suggests that the road system was the only limiting factor to the size of the German force to be committed. When the Germans attacked Greece, they had not yet set the date for attacking Russia. The decision had been made, but that was all. In the event, the Balkans campaign and the battle for Crete delayed the attack on Russia. Some have suggested that this was a decisive factor in the German attack stalling in front of Moscow when winter hit in earnest. This is based on the account in Vol.II of the Australian Official History.