Stülpnagel remained in the Reichswehr after the war. Opposed to democracy, he worked to overthrow the Weimar Republic and became an avid Nazi. In the 1920s, Stülpnagel served as inspector of transport troops and was promoted to Generalmajor (U.S. equiv. brigadier general) in 1929. In his post, he feuded with Colonel Heinz Guderian over the utility of tanks and armor. Stülpnagel issued orders that specifically prohibited the development of tactical plans using concentrations of armor and instead advocated use of tanks in infantry support. He then joined what would become the Luftwaffe, rising to the rank of General der Fliegers (U.S. equiv. lieutenant general). He returned to the army in 1939.
Retired from the army that same year in Adolf Hitler's purge of generals, Stülpnagel was recalled to active duty at the rank of General der Infanterie (U.S. equiv. lieutenant general) in 1940. Too old to be assigned a field command, he served on the French armistice committee and was instrumental in convincing Hitler to allow the new Vichy French government some autonomy in its control of France's colonial possessions.
Hitler then appointed Stülpnagel military governor of the German-occupied portion of France. In this post, Stülpnagel served as a moderating force between the French and hard-line German elements led by Heinrich Himmler and the Schutzstaffel (SS). Stülpnagel's goal was to retain military control over police functions. However, he also endorsed harsh measures against the Resistance, and he even advocated the death sentence for those caught listening to the British Broadcasting Corporation. By March 1941, deportations of French Jews had begun.
After police powers were transferred to the SS, Stülpnagel resigned his post and was succeeded in March 1942 by his cousin, General Karl Stülpnagel. Charged after the war with crimes in France, Otto von Stülpnagel hanged himself in Paris on 6 February 1948 rather than stand trial.
Burrin, Philippe. France under the Germans: Collaboration and Compromise. New York: Free Press, 1996.; Jackson, Julian. France: The Dark Years. Oxford, UK: Oxford University Press, 2001.; Paxton, Robert O. Parades and Politics at Vichy: The French Officer Corps under Marshal Pétain. Princeton, NJ: Princeton University Press, 1966.