Krebs was discharged in March 1919, leaving him free to begin studies in Germanistics, history, national economics, and English language in Würzburg, Tübingen, Marburg and Frankfurt am Main.

[3] Owing to an article published early in 1932 that was critical of Chancellor Kurt von Schleicher's cabinet, Krebs was upbraided by Adolf Hitler personally, removed as editor and expelled from the Party on 20 May 1932.

[4] With the beginning of the Russian Campaign, Krebs was called up for service and assigned as special leader of the Propagandabteilung Ostland and took over cultural affairs in the cities of Riga and Tallinn.

Through his acquaintance with Fritz-Dietlof von der Schulenburg, to whom he had been introduced in 1942, Krebs knew in advance about the resistance's plans to overthrow the Führer and also about the attempt on Hitler's life.

[4] In his autobiographical chronicle, published in 1959, "Tendenzen und Gestalten der NSDAP" ("The NSDAP's Tendencies and Shapes"), Krebs portrayed himself as a contemporary who was at first impressed by Nazism's political ideas and goals, but who after personal experience with Hitler's dictatorial leadership style and the "incompetence in the NS Führer State" withdrew, disappointed, from political life.