How many countries were effected by world war 1?

World War I involved many countries across multiple continents, with around 30 nations participating directly in the conflict. The primary belligerents were divided into two main alliances: the Allies and the Central Powers. Major countries affected included the United Kingdom, France, Russia, Germany, Austria-Hungary, and Italy, among others. The war had far-reaching consequences, impacting not only the warring nations but also many regions around the world.