Why Do Mass Expulsions Still Happen?

January 30, 2023 marks 100 years since the signing of the Lausanne Convention—a treaty codifying the compulsory “population exchange” between Greece and Turkey. An estimated 1.5 million people were forcibly expelled from their homes: over one million Greek Orthodox Christians from the Ottoman Empire and 500,000 Muslims from Greece.

This population exchange was not the first such agreement, but it was the first compulsory exchange. Turkish nationals of the Greek Orthodox religion and Muslim Greek nationals did not have the option to remain. Further, Greek and Muslim refugees who had fled the Ottoman Empire and Greece, respectively, were not allowed to return to their homes. Only small populations in Istanbul and Western Thrace were exempted from the treaty.

The population exchange between Greece and Turkey is an example of the broader phenomenon of mass expulsion—a government policy to systematically remove an ethnic group without individual legal review and with no recognition of the right to return. Far from an isolated incident, the Lausanne Convention was one of 19 population “transfers” or “exchanges” throughout Europe in the early twentieth century. These expulsions occurred with the stroke of a pen, but mass expulsions also occur at the point of a sword. Governments use violence to force out “undesirable” groups by destroying their homes, appropriating their assets and income, and in some cases, killing members of the group to encourage others to flee.

Although mass expulsion is rare, it is recurring. Between 1900–2020, governments expelled over 30 million citizens and non-citizens in 139 different episodes around the world.