The causes of the World War I are as follows:

• Formation of two Hostile Alliance: France and Germany were arch-rival. To isolate France and to secure support to his policies, Bismarck made a secret alliance known as 'Dual Alliance' with Austria-Hungary in 1879. Italy joined this alliance in 1892. Now it came to be known as Triple Alliance or Central Power.
• After Otto Van Bismarck resigned from his post in 1890, France made two different treaties with Russia and Britain and hence triple estate was formed of France, England and Russia. These two groups were likely to fight to each other at any time.
• Aggressive nationalism: Nationalism can be an evil force and a curse to humanity. It is usually based on the slogan 'My country', right or wrong, is the greatest. It showed the seeds of the First World War.
• Anarchy and absence of peace keeping organization: The big and powerful nations began to do what they liked. They ignored justice and values. 'Might is right' was the order of the time. The strong nations openly violated international laws. There was no such international peace keeping organization which could control the explosive situation prevailing in Europe.
• The immediate cause: Archduke Franz Ferdinand was the hero of Austrian throne. At a time he was travelling throughout the streets of Sarajevo, the capital of Bosnia, along with his wife Sophie Chotek, a Black Garvilo Princip murdered the couple, shooting from nearby on 28th June 1914. This incident sparked off the First World War.