Main causes of World War I It was in relation to the July Crisis of 1914.

These were militarism and armaments, nationalism, and imperialism.

Because Britain had a large navy, Germany wanted a large navy too.

Vienna seized the opportunity presented by the assassination of the archduke to attempt to destroy its Balkan rival Serbia.

Main reason, The Triple Entente was an “association between Great Britain, France, and Russia, the nucleus of the Allied Powers in World.