The peace settlement following the First World War, including the Treaty of Lausanne, created a novel international legitimacy as a pillar and an integral part of a new, value-oriented liberal international system. In the interwar period this international legitimacy sustained the full-scale attack of the forces of revisionism, most prominently Nazi Germany, but its concept triumphed during the Second World War. Moreover, this new international order in the Near East signaled the definite, though sudden and violent, transition of the region from imperial governance to the model of the nation-state. The paper discusses these two salient functions of the Treaty.