Citation.

This is coolbert:

August Von Mackensen a supporter of the Adolph Hitler Nazi regime but more correctly thought of as a Monarchist in the same category as a Ludendorff or a Von Trapp.

Hoping for a restoration of the German Empire and monarchy.  Hitler seen also as a man the antidote also to the weakness and inept performance of the Weimar Republic.

German honor restored from the perspective of Von Mackensen.

But consider this extract from the wiki as copied in entirety with my commentary: [my emphasis in all cases]

"As a man becomes older, he has to watch carefully that age has not reduced his creativity. After reaching the age of 90, I have decided not to involve myself any longer with matters that are not concerned with my private life. However, I am still the most senior German officer. Many turn to me, sometimes with wishes, but more often with their concerns. During these weeks our concern is with the spirit of our unique and successful Army. The concern results from the crimes committed in Poland, looting and murder that take place before the eyes of our troops, who appear unable to put an end to them. An apparent indifference has serious consequences for the morale of our soldiers and it is damaging to the esteem of our Army and our whole nation. I am sure that you are aware of these events and that you certainly condemn them. These lines intend to convey my daily growing concern at the reports that constantly reach me, and I have to ask you to take up this matter with the highest authority. The messages I receive are so numerous, many come from high ranking persons and from witnesses. As the most senior officer I cannot keep them to myself. In transmitting them to you, I fulfill my duty to the Army. The honour of the Army and the esteem in which it is held must not be jeopardized by the actions of hired subhumans and criminals. sieg heil" - - Mackensen in communication with serving German Field Marshal Walther von Brauchitsch: 4 February 1940.

Concerns! Events! OH we know what is being discussed here, don't we? Hardly I think elaboration necessary.

That elevated sense of honor a "reactionary" moral virtue as despised by Adolph Hitler? That "concern" of Von Mackensen valid, events however transpiring without amelioration, the results plain to all.

coolbert.