In what ways does the Great War, especially the Treaty of Versailles, continue to shape the world today?

World War I (1914–1918) and the Treaty of Versailles (1919) changed the world in many ways. At least four of the changes it wrought are still evident today.
Autocracy was badly damaged by the war. Four empires—the German, Russian, Austrian, and Turkish—were destroyed. Their autocratic leaders were overthrown, and the ruling families forever lost their thrones.
Nationalism became a potent force after the war. Three nations were carved out of the old Austro-Hungarian Empire. Others came out of the old Russian Empire. Ethnic tensions flared after the war, especially in eastern Europe.
The United States emerged from the war relatively unscathed. Europe, on the other hand, was devastated. The U.S. has held onto its relative power compared with Europe for the last century.
Finally, the League of Nations was created after the war. Despite its ultimate failure, it gave the world a model that would be replicated after World War II with the creation of the United Nations.