How did countries separate?

Countries have separated through various means, including wars, treaties, and decolonization. Historical events like the dissolution of empires, such as the Austro-Hungarian and Ottoman Empires after World War I, led to the creation of new nation-states. Additionally, movements for independence and self-determination, often sparked by nationalist sentiments, have played a significant role in the separation of countries. Modern examples include the peaceful splitting of Czechoslovakia into the Czech Republic and Slovakia in 1993.