As far as I can tell, Germania appears to be a novel. But it's certainly true that Donitz and others were desperately grasping at straws to try to persuade the Western Allies to join them in an anti-Bolshevik crusade. I've just recently read a fascinating book called Tapping Hitler's Generals.   British intelligence set up a means to record, between 1942 and 1945, conversations of German high-ranking prisoners--officers-- they had set up in an (amazingly luxurious) estate in North London.   The Germans discussed freely--and argued with each other, forming cliques etc., often on the basis of attitudes toward Hitler, and dealt with questions of the war in great detail. They appear to truly have not realized they were being recorded, since some gave incriminating anti-Semitic remarks and discussed atrocities, etc.

Among many other things, the excuses given are amazing, as are the stories of how some at least tried to bring soldiers who committed atrocities--against Russians at least,--to justice. And how any attempts to do so were steamrollered by higher authorities.