28. What could realistically have been a result if D-Day - Operation Overlord, June 6, 1944 - had never taken place, everything else up to that point being the same?
From Quiz Analyzing Battles of World War II
Answer:
Greater parts of Europe might have become Soviet controlled
Of course, agreements on the zones of control in Europe were made in various conferences between the Allies. But it is certainly the question if Stalin would have abided by these agreements if they were not enforced by the presence of Western troops on the ground. For instance, a greater part of Germany and/or Austria could have become Soviet controlled.
This is not to diminish the sacrifice of so many Allied soldiers, who bravely fought in Europe. But Germany was already well on its way to defeat at this point; the Soviet operation, Bagration, had just destroyed the Army Group Centre on the Eastern Front. It would not have taken the Red Army ten years to defeat Germany, even if some divisions would have moved from France to the east as no invasion seemed to be happening. Exactly when Germany lost the war on the Eastern Front, and thus the war as a whole, is debatable; cases can be made for June '41, December '41, November '42, July '43, etc., but it would have certainly happened by June '44.