In other cases, attempts to create ethnically homogeneous countries resulted in significant population displacement and violence. For example, the Treaty of Lausanne of 1923 led to a population exchange between Greece and Turkey, resulting in the displacement of over 1 million people. The partition of the Ottoman Empire also led to the creation of new states with diverse ethnic populations, such as Iraq, Syria, and Lebanon, which have faced ongoing ethnic conflict and instability.
Overall, the attempts to create countries along ethnic lines following World War 1 were largely unsuccessful, as they often resulted in internal conflict, population displacement, and ongoing instability.