Although he was initially an enthusiastic supporter of Nazism because it opposed the Treaty of Versailles , he was quickly disillusioned by 1934 when the '' Schutzstaffel '' ( SS ) extrajudicially murdered many SA leaders and political opponents , including two generals , in the Night of the Long Knives ( 30 June to 2 July 1934 ) . The events of the 1930s , such as the 1938 Blomberg – Fritsch Affair , further strengthened his antipathy to the Nazis . He regarded the '' Kristallnacht '' ( state-sanctioned , nationwide pogrom of Jews ) as personal humiliation and degradation of civilization . He thus sought out civilians and officers who opposed Hitler , such as Erwin von Witzleben , who dissuaded Tresckow from resigning from the Army , arguing that they would be needed when the day of reckoning came . By the summer of 1939 , he told Fabian von Schlabrendorff that " both duty and honor demand from us that we should do our best to bring about the downfall of Hitler and National Socialism to save Germany and Europe from barbarism . " In the campaign against the Soviet Union , Tresckow resumed his resistance activities with renewed urgency . He was appalled by the Commissar Order , the treatment of Russian prisoners of war , and in particular the mass shootings of Jewish women and children by the Einsatzgruppen behind the lines . When Tresckow learned about the massacre of thousands of Jews at Borisov , Tresckow appealed passionately to Field Marshal Fedor von Bock : " Never may such a thing happen again ! And so we must act now . We have the power in Russia ! " Army Group Centre staff included Lieutenant Colonel Georg Schulze-Büttger , Colonel Rudolf Christoph Freiherr von Gersdorff , Major Carl-Hans Graf von Hardenberg , Lieutenant Heinrich Graf von Lehndorff-Steinort , Lieutenant von Schlabrendorff , Lieutenant Philipp von Boeselager and his brother Georg von Boeselager , Lieutenant Colonel Hans-Alexander von Voss and Lieutenant Colonel Berndt von Kleist among others , many of them from Tresckow 's old Infantry Regiment 9 . The headquarters of Army Group Centre thus emerged as the new nerve centre of Army resistance . At the end of September 1941 , Tresckow sent his special operations officer Schlabrendorff to Berlin to contact opposition groups and declare that the staff of Army Group Centre was " prepared to do anything . " This approach , made at the height of German expansion and the nadir of anti-Hitler opposition , represented the first initiative to come from the front and from the Army , as Ulrich von Hassell noted in his diary . Schlabrendorff continued to serve as liaison between Army Group Centre and opposition circle around General Ludwig Beck , Carl Friedrich Goerdeler and Colonel Hans Oster , the deputy head of Abwehr ( German military intelligence ) who was involved in a 1938 coup attempt against Hitler ( Oster Conspiracy ) . Oster 's recruitment of General Friedrich Olbricht , head of the General Army Office headquarters , in 1942 linked this asset to Tresckow 's resistance group in Army Group Centre , creating a viable coup apparatus
Kristallnacht
Kristallnacht
Henning von Tresckow