The basic idea is that, like King Arthur, Hitler isn’t dead, but instead lives on in the Polar Center. For Arthur this center is Avalon, but Avalon goes by many names; Valhalla, Shambala, etc. For Hitler this center is Antarctica, specifically Neuschwabenland
That’s right, Hitler escaped! He is wounded, his armies destroyed, but he still lives sleeping in Avalon. Like Charlemagne, Frederick I, and Frederick II, Hitler will return to set things right someday, to complete his work.
While the main parts of Hitler’s armies were destroyed, not all was. Neuschwabenland was home to a submarine base, but possibly more than just conventional weapons. Die Glocke(The Bell) was stored in Antarctica, where they defend the entrance to Agartha and await Hitler to heal.