The First World War arose because of large-scale contradictions between the great powers associated with competition. Recently, new scientific questions have been raised about the relations of world powers, as well as about the problem between military-political blocs. One of them was the military-political Union between the Ottoman Empire and Kaiser's Germany during the First World War. Relations between Turks and Germans, who had been in close cooperation since the 1980s, developed over time. Before the First World War, political relations between the two countries reached the level of an alliance. At the beginning of the war, the Ottoman Empire and Germany concluded an alliance treaty and entered the war within the framework of the Triple Alliance. This scientific article discusses the history of the adoption of the Treaty of Union between the Ottoman Empire and Germany in the First World War. A scientific analysis of the history of the adoption of the Treaty on the Union is being carried out. New conclusions are made about the prerequisites and reasons for the entry of the Ottoman state into the First World War. The political positions and principles between the parties are determined and the strategic plans of the Ottoman state during the First World War are studied.