he's put the Montague plan into effect, killing millions of Germans.
He has ensured that Fascism will never die (forget far-right/alt right groups of today I mean old school hitlerism in Germany itself. the man has retroactively validated half the conspiracy theories that got the man into the Chancellory in the first place). In the future surviving Germans will tell thier children this whisper in thier ears that he was right. Democracy, Liberalism, and Capitalism are dead in the hearts and minds of the Germans.
He's handed hundred of thousands, maybe millions of people, over to Stalin, a man only considered less bad than Hitler because of the method, not body count. And he's made sure Japan will never be the stanch partner we had OTL nor ever consider a path in line with America or peace.
Worse of all, he's shot his own ethnicity in the back at the whims of a made man and an antisemite! White is worse than a fool, a dictator, or a traitor. He something else, whose and misbegotten, graceless in all things, Caligula, Claudius, Commodus, and now White.