All of the following factors contributed to the outbreak of war in Europe in 1914 except Select one: the assassination of Archduke Francis Ferdinand. Balkan desire for independence. the complicated defense alliances. European imperial ambitions. the sinking of the Lusitania.
The main cause of the war, was the Assassination of Arch Duke Franz Ferdinand. The sinking of the Lusitania only cause the U.S. to enter and help the British and French.