Yesterday marked the anniversary of the Allied landings at Normandy in 1944. D-Day was one of the largest amphibious operations ever performed. Over 150,000 British, American, Canadian and other soldiers took part in the combined assault by air and sea on the beaches of Normandy to mark the first step in the liberation of France from the Axis. The D-Day landings are often marked as a crucial point in the war, and indeed they were. The landings opened up the much-needed second front in Europe and greatly hastened the liberation of France and the fall of the Axis. However, what would have happened if D-Day had failed? D-Day largely succeeded thanks to an incredible effort of misdirection by the Allied powers as to the location of the invasion. The efforts of this campaign known as Operation Fortitude led Hitler to believe the Allied landings would take place at the Pas-de-Calais, the narrowest stretch of the English Channel, with a simultaneous landing in Norway. The deception of Operation Fortitude worked and Hitler ordered a large defensive force at Calais ahead of D-Day, and continued to keep 15 divisions at Calais even after the landings under the belief that D-Day remained a diversionary tactic.
The most plausible way to reverse or at least slow the advance of the Allies in northern France after D-Day is to have these divisions reinforce the Atlantic Wall in Normandy. Let us assume that the Allied invasion does still somewhat succeed, but is largely confined to the area around Caen, with attempts to take Cherbourg fail. The failure to capture Cherbourg would deny the Allies a deep-water port and delay supplies from being shipped across the Atlantic. However, there is still the issue of preventing long-term success of D-Day. In our history, despite a storm in the English Channel disrupting supply shipments in mid-June, the Allies still managed to land over one million men at Normandy by the end of June 1944. Additionally, Allied air superiority had already been assured over the Channel and northern France in preparation for the landings. However, for the purposes of this counterfactual, we shall assume that the Normandy landings are confined to the area around Caen for the large part of 1944.
While the invasion of Normandy is stalled, the other European fronts would still be advancing. On the Eastern Front, the Soviet would still launch Operation Bagration in mid-June. By the beginning of August, the Red Army had advanced from Vitebsk pushing the Germans all the way back to Warsaw and eliminating the German Army Group Center. This is probably the biggest singular defeat the Germans suffered during World War II, even in our history. But with Normandy stalled, Bagration will have an even bigger impact on the war. With the Soviets reaching the outskirts of Warsaw earlier and the British being seen as more incapable in Normandy, Stalin may be more willing to let the Soviets assist the Warsaw Uprising. As a strategic move, Soviet assistance would make the Red Army be seen more as liberators in Poland. A successful Warsaw Uprising would also lead to the Polish resistance going through with the Krakow Uprising. If the Krakow Uprising is successful, it would strike a major blow to the Axis as Krakow was the center of the Polish General Government.
Meanwhile on the Italian front, one of the most significant events happened just before D-Day. On June 5, 1944, Rome was liberated by Allies forces, becoming the first Axis capital to fall. Not much would change from our history in Italy, but the lack of breakthroughs in Normandy may cause the Allies to scrap the plans for the landings on the French Mediterranean coast under Operation Dragoon. No Dragoon would mean more forces focused in Italy, and a quicker advance north up the peninsula. There may be enough acceleration of Allied movements to cause a breakthrough of the Gothic Line, the last Axis line of defense on the Italian peninsula, in 1944 instead of in the spring of 1945 as in our history.
With this in mind, how much would a less successful Normandy invasion have affected the outcome of the war in Europe? The war would almost certainly last longer without a significant front being opened up in northern France, but the overall course of Germany’s surrender would likely only be delayed by a few months, possibly into the early months of 1946 at the latest. Most of the noticeable historical changes would start occurring in the politics surrounding the post-World War II division of Europe and the start of the Cold War. The stalling of the Normandy invasion would present to the Soviets a seeming military weakness in the Allied forces and especially the British. The cancelling of Operation Dragoon would also likely make Stalin demand more concessions from the Western Allies in the Yalta Conference, since the United States and United Kingdom would have gone back on their commitment to open a front in southern France in 1944. Some possible concessions would be no partition of Berlin, though the western Allies agreeing to that is not likely. More probable are a minor adjustment in the Soviet-Polish border to the Soviet border after the Molotov-Ribbentrop Pact, or Stalin not conceding a French occupation zone and having Germany and Austria only divided among the Us, UK, and USSR.
The timeline of WWII in 1944 on Wikipedia provides a good summary of the Allied advance.