 In April 1918 , after the German @-@ Russian Treaty of Brest @-@ Litovsk , Austrian Foreign Minister Count Ottokar Czernin made a speech attacking incoming French Prime Minister Georges Clemenceau as being the main obstacle to a peace favouring the Central Powers . Clemenceau was incensed and , after seeing the Emperor Charles 's letter of 24 March 1917 , had it published . For a while , the life of Sixtus appeared to be in danger , and there were even fears that Germany might occupy Austria . Czernin persuaded Charles to send a ' Word of Honour ' to Austria 's allies saying that Sixtus had not been authorised to show the letter to the French Government , that Belgium had not been mentioned , and that Clemenceau had lied about the mentioning of Alsace . Czernin had actually been in contact with the German Embassy throughout the whole crisis and attempted to persuade the Emperor to step down because of the Affair . After failing to do so , Czernin resigned as Foreign Minister . 
