What were the underlying causes of the outbreak of the First World War?

There were four main causes of the First World War before the assassination of Archduke Franz Ferdinand, nationalism, imperialism, militarism and alliances. Nationalism: this caused aggression between the nations involved as a result of patriotism. Imperialism: Britain and France both had colonies in Africa. Germany wanted a 'place in the sun' as well and this caused tension, contributing to the outbreak of war. Militarism : the arms race also contributed to WWI starting. Countries were expanding their military reaches (e.g. the British Navy) and this caused growing paranoia and tension. Alliances: the Triple Alliance (Germany, Italy and Austria-Hungary) and the Triple Entente (France, Britain and Russia) were formed in order to provide each other with assistance in case of war breaking out. This again caused tension and unease and also led to the war.