World War one broke out for a variety of reasons. Some were long-term factors and others were short-term factors. In further detail I will explain each of these factors and what triggered the World War one. The first long term factor that played part in the lead up to the Great War was the system of alliances which I believe is the most important factor. An alliance is an agreement made between two or more countries to aid each other if one was attacked. When countries agree to an alliance, those countries then become what is known as Allies. The two alliances at the time of the World War one was the Triple Entente which was made up of Britain, France and Russia and the Triple Alliance which contained Germany, Italy and Austria-Hungary. I personally think this was the most important reason as when you declared war with one country, the other countries in the alliance had no choice but to declare war also which meant you were fighting with at least one or two more countries making it a bigger and greater war.
The first point I would like to make is Nationalism which was a long term factor. Each country felt their country was the best, they wanted their nation to be above all others and they tried a lot to promote their culture and interests to those of other nations. Nationalism is when a country wants to be independent, in this case, it was Serbia. Serbia desired to break free from the influence of larger nations such as Austria-Hungary. Different nationalist groups within Serbia and Austria-Hungary also wanted freedom from the states in which they lived. Larger nations tended to dominate trade routes and exports. As Austria-Hungary did not want Serbia to be independent, Serbia rebelled by killing Archduke Franz Ferdinand, the heir to Austro-Hungarian throne. All of this led to the formation of Germany in 1871. The next long term factor is Imperialism, this is when a country takes over new lands or countries and makes them a subject to their rule.