At the Paris Peace Conference following World War I, President Woodrow Wilson promoted national self-determination as the guiding principle in drafting the peace treaties. But this principle could not accommodate national and ethnic minorities. Therefore, the Allied Powers required new or expanded states to sign minority treaties guaranteeing the rights of inhabitants regardless of birth, nationality, race, language, or religion, beginning with Poland in conjunction with the Treaty of Versailles. Czechoslovakia, Romania, Austria, Greece, and the Kingdom of Serbs, Croats, and Slovenes signed analogous minority treaties.

The Treaty of Sèvres with the Ottoman Empire made some provision for minority rights. But Mustafa Kemal, who headed a nationalist movement against the sultanate, repudiated the treaty and proceeded to drive the Greeks out of Ottoman territory over which the treaty had given them control. In its place, the Allied Powers signed the Treaty of Lausanne with Turkey.

Taking a different approach with regard to minorities, the Lausanne Conference agreed to the first internationally ratified compulsory population exchange with the Turco-Greek convention, which endorsed the uprooting of 1.5 million Greek Orthodox from Asia Minor and their resettlement in Greece. Despite the trauma that the exodus inflicted on the refugees, the exchange came to viewed as a success. For example, the Polish specialist in population movements Alfons Krysiński wrote in 1931: “From a multilingual, multinational state, [Turkey] became a state of far advanced national consolidation. . . . A further consequence of the consistent policy with regard to migration movements is that the Turkish republic finally rid itself of irredenta of national minorities in its own country” [“Tendencje rozwojowe ludności Polski pod względem narodowościowym i wyznaniowym w dobie powojennej,” Sprawy Narodowościowe 5, no. 1 (Jan.-Apr.1931): 60.] Thanks to a consensus on this issue among the Great Powers, following World War II, the United States, Great Britain, and the Soviet Union sanctioned the more or less forced migration of some 30 million Europeans from their homes. The Treaty of Lausanne constituted a major precedent justifying the decisions that underpinned these actions.