Causes of WW1

World War 1 was a big part of history. It all started when a big leader was assassinated. It was an aggregation towards other countries which was supported by the nationalism of the European nations. Economically competition was war where military alliance and attacked other countries. The World War 1 lasted for four years and three months. There was an alliance system which was started by Bismarck. The system included many countries such as Germany and other countries.