Germany and Austria-Hungary are meant to be close allies, but relations between their army chiefs are less than cordial. A source of tension is the frequency with which German troops have had to come to the aid of the Austro-Hungarians. What is meant to be a relationship of equals has increasingly become one of client and patron, with all the petty resentments that entails.
Relations completely broke down when Germany’s Falkenhayn declined a request by Conrad for German troops to assist with a planned Austro-Hungarian offensive against Italy. Conrad was so piqued that routine communication between the German and Austro-Hungarian general staffs came to a halt.
Now after more than a month of sulking the German and Austro-Hungarian general staffs at last resume contacts with each other. However, in the period of silence the German and Austro-Hungarian commanders have made their plans for 1916 without reference to each other, and they are not going to change them now. Nor does Falkenhayn feel any need to inform Conrad of his forthcoming offensive at Verdun. The die is cast: Germany and Austria-Hungary will be on divergent paths this year.
Falkenhayn (The Great War Blog)