The biggest problem with establishing WW2 history is the fact that all the so-called death camps were in territory taken by the Soviet army (and held by them after the war). The Bolsheviks had long sought to destroy Germany and I believe they did everything they could after the war to continue the assault on the German people, who might arguably be the most psychologically warped people on the planet. No one else is so dedicated to divorcing themselves from their own history.