This week marks the anniversary of D-Day. Every year, historians argue what would have happened had D-Day failed. This year, I’ll finally add my two cents.
I think it is clear that Germany would still have lost the war, for a failed invasion would not have changed the fundamental dynamics it faced. Germany was fighting a war on multiple fronts against enemies committed to its destruction: in the east against the Soviet Union and in Italy against a combined force of Western allies. In the occupied countries of Europe it confronted ever-more bold resistance and partisan movements. Allied bombing raids were devastating German cities day and night. And part of the German army would always have to remain vigilant against an invasion taking place somewhere in Western Europe from Norway down to France.
Supposing D-Day had failed, it is highly doubtful that the Americans or British would have given up after all they had expended to win the war and because of their ideological distaste for Nazism. My bet is that they would have doubled down on the campaign in Italy. This would have put them in a position ultimately to invade Germany from the South. I also suspect that they would have further increased bombing raids to put further pressure on the German economy, infrastructure, and morale. And of course, the Soviet army would have continued its relentless westward push into Germany.
Would Germany have been able to shift some of its army west to fight the Soviets had D-Day failed? Yes, but that number would necessarily have had to be limited. Remember, Germany was fighting the Western allies in Italy. It also needed to retain at least some forces in the occupied countries to keep order and prevent rebellion. Lastly, there would still have been a specter of an allied invasion in the West, which would have necessitated keeping some forces on alert in countries like France and Belgium. I honestly think that the Western allies led by Churchill might have considered an invasion of Greece to force the Germans to fight multiple enemies in the East, something which Stalin would normally have opposed, but which he might have come to accept it when confronted with new German armies blocking his advance.
Ultimately, these circumstances always conspired to keep Germany from winning by a late date like 1944. The next interesting possibility to consider is what the fate of post-war Europe would have been like. There are many who argue that Stalin would have conquered more of Germany and central Europe since the Western allies would not have a beachhead from which to push east. But this makes three assumptions. First, it assumes that the Western allies would not have launched a second invasion of Western Europe shortly after D-Day that enabled them to move against Germany. Second, it assumes that that the Western allies would not have made a stronger effort to move through Italy that enabled them to attack Germany from the South, a distinct possibility. Lastly, it also assumes that Germany would not have been able to transfer some manpower from Western Europe to prolong the Soviet advance (which would have given the allies more time to recoup their losses and launch another invasion).
All of this is to say that it is actually far from clear whether the Soviets would have managed to dominate continental Europe. I think the likeliest scenario is that the Western allies would have simply added to their push in Italy and looked for the soonest possible date to launch another invasion. With some extra German troops tying the Soviets up in Eastern Europe, they would have had extra time to get to Germany.
What do you think would have happened?