The main causes of World War I can be narrowed down to general causes that had been building up for a long time, including Militarism, Alliances, Imperialism, Nationalism, Industrialization (mostly only pertaining to this war because of increase in technology of weapons and lack of up to date tactics), and the event that sparked the whole war, the Assassination of Archduke of Austria-Hungary, Franz Ferdinand by a Serbian man. Austria Hungary, supposedly looking to start a war with Serbia sent a threatening document. After this happened Russia, allies with Serbia began to prepare forces to back up their ally. Germany became worried and also prepared forces to help their ally, Austria-Hungary, possibly take on Russia. Thus the entangled alliances began, and so forth each country was dragged into the war in order to back up their ally. The long term cause of militarism played a role because everyone was building up their armies to prove power and strength, so they were all in theory ready for war. Imperialism was at a peek movement during this time and countries were in constant argument about rightful territories and colonies. Lastly, every country had a booming sense of nationalism that their country is they best and were willing to go to extremes to prove it; an excellent example: Gavrilo Princip killing Franz Ferdinand proving his loyalty to his country.