Causes of WWI World War I lasted from 1914 to 1918. At the time it was called the Great War. People thought this was going to be “war to end all wars”. Although many nations were involved, most of the fighting took place in Europe, especially France. The United States did not become involved militarily until 1917. Long Term Causes of WWI: Think MAIN! M: Militarism. A: Alliances Central Powers Allied Powers (aka Allies) Germany Great Britain Austria- Hungary Belgium Serbia United States Bulgaria France Ottoman Empire Russia I: Imperialism N: Nationalism Short term cause of WWI June 1914: A Serbian man shot and killed Archduke Franz Ferdinand the heir to the throne of Austria-Hungary. THIS STARTED WWI! July 1914: In response, Austria-Hungary declared war on Serbia July-August 1914: One by one, the other nations of Europe were pulled into the war because of their alliances