Do you ever wonder what started World War I? Who could possibly start such a huge conflict? World War I, commonly referred to as the Great World War, was not started because of a single event but, for three primary reasons: militarism, alliances and imperialism. Militarism is mainly remembered to be one of three main causes of the first world war, but it is more than that, it is when countries are pressured to build up their military because they are intimidated and jealous of others who are stronger based on their military. All the countries would also build their military up also because they wanted to be the strongest. With all the countries aiming to be the strongest it caused tension and competition leaving them all on edge ready