While the Operation Barbarossa (Hitler’s invasion of Russia) and Soviet late war operation against Germany were impressive; neither operation was an amphibious one against an entrenched enemy. McCain’s claim is generally regarded by many miltary historians as correct. That D-Day IS the greatest invasion in history is undeniable, considering the scope, coordination and breaching of Hitler’s Atlantic Wall.
Also, Hitler knew that he had convinced Stalin that Stalin’s own spies were lying when they told “Uncle Joe” the exact date Barbarossa would begin.
Thanks for making that point, the problems associated with landing 1/100th of of either of the land operations numbers amphibiously while opposed is way greater than that of either Barbarossa or the Russian Spring offensive cycles.
It is however, worth remembering that during the D-Day landings, the allies had total air and naval superiority and they were fighting against forces that were for the most part, the dregs of the German Army. Those too old, ill, or green to fight on the Eastern Front, which was the front which had top priority for the Nazis. Both the Germans and the Russians were throwing the best they had at each other....