The Allies and the Entente.
World War one was the first great war. It was the biggest war the world had seen and involved many countries.
123 countries involved in the war
Pretty much anyone involved in the war.
There were not only two countries.
Because most of the major countries of the world were involved in the fighting.
World War I was also called 'The Great War'. It was given that name because it involved all of the world's great powers or most influential and important countries.
Switzerland, Turkey, Portugal, Sweden, and Spain were neutral countries in World War 2.
Most Asian countries were involved in World War 2