Why was operation overlord a success?

Answer 1

Several reasons. A military maxim is that to attempt to be strong everywhere is to be strong nowhere. The Germans had the task of defending the entire coast of Western Europe, from the north cape of Norway to the Spanish border. Previous Allied amphibious attacks had provided examples from which the Germans could infer that the Allies would only make the effort at a place where land-based aircraft, from the United Kingdom, could cover the beaches, but this still involved hundreds of miles of coastline. In the event, the Germans vaunted Atlantic Wall defenses, upon which they lavished millions of man-hours, hundreds of thousands of tons of concrete and steel, and many troops, were breached in a single day. Spread out as they had to be the German defenders were or generally mediocre quality at first, with "static" divisions of older men and invalids, and of impressed Polish soldiers who barely understood German. There was only one good division in the entire sixty-mile wide landing area. Other factors included that the Allies had attained complete air superiority, almost accidentally. A side effect of the strategic bombing of Germany and occupied Europe was that it forced the German air force to defend against the raids, and with the introduction of new, better Allied fighter aircraft in early 1944, the Germans had lost so much strength in the air that their Luftwaffe was a non-factor on D-Day and thereafter. Similarly, the German navy was a no show on D-Day. Preparatory Allied air raids over the preceding months had so degraded the French railroad network and bridges as to isolate the battlefield, and clouds of fighter-bombers constantly overhead made the movement of any German reinforcements to the beachhead area all but impossible. The Deception Plan was successful in deceiving the Germans into believing that the Normandy landings were merely a feint, and that the real landings would eventually come at the Pas de Calais, north of the Seine River. This led to the retention of the entire 15th Army north of the Seine, uninvolved, while the Normandy campaign played out. Rommel and his immediate superior had been unable before the invasion to agree on a strategy. Rommel thought that the invasion could only be defeated at the water's edge, and that the landing force must immediately be hurled back into the sea. Rundstedt did not think this would be possible, given the wide area where the Allies might land. Their disagreement was kicked upstairs for Hitler to decide, the crucial factor being which of them would have control over the small reserve force of German armor. Hitler resolved the dispute by deciding to retain personal control of those armored divisions himself, and, when the invasion came Hitler was asleep, in a drug-induced fog, and no one dared wake him for orders to move those divisions. So, if Rommel was right and the invasion had to be defeated immediately if it was to be defeated at all remains an untested theory. The Overlord Plan encompassed the actual landings and the following ninety days. By D+90, most of France was liberated, a far better result than the planners had hoped. The Germans cooperated is this, in moving practically all their troops in France south of the Seine to the beachhead area, to try to encapsulate the Allied force. Once the Allies cracked out through this encircling crust and began to roll across France, there was nothing left for the Germans to use to stop them.