And you may well be right - after all, the logistics determines what firepower may be brought to bear.

But I must admit I'm cynical on the matter. By early 1943, the Battle of the Atlantic was a foregone conclusion, and the Royal Navy was in control of the English Channel. It wouldn't have been easy (we had air superiority, but not as overwhelmingly as in 1944, and the lack of "mulberries" for docking would have been problematic), but I think we could have invaded in June and successfully supported an invasion...and that the reason we didn't do so was Churchill's anger at Russia's logistical support of Germany prior to Operation Barbarossa.