What are the main factors that caused World War I (1914-1918)?

In order to better understand the causes of WWI, we use the following acronym- ANIMAL, which stands for

Alliances: Triple Alliance (1882) of Germany, Austria-Hungary and Italy vs Triple Entente (1907) of the UK, France and Russia. Other alliances: Franco-Russian Alliance (1894), Entente Cordiale between France and Britain (1904)

Nationalism: France's resenment towards Germany the loss of Alsace-Lorraine in the Franco-Prussian War (1870-1871) 

Imperialism: 'The Scramble for Africa' (1884), Kaiser Wilhelm II's desire (Weltpolitik) to expend the German colonial empire at the risk of alienating Britain and France. Prime example: Morrocan Crisis of 1905/1911

Millitarism: naval arms race between Britain and Germany with the battleship 'Dreadnaught' as a product of that race. Increased milllitarisation in major European powers in preparation for an inevitable war. 

Autocracy vs Democracy: Germany was an autocratic monarchy where the Kaiser was responsible for making the final decision. Britain was a parliamentary democracy where political decisions, especially regarding millitary involvement, were shaped by public opinions.

 

List of events: notable events include 

The Morrocan Crisis of 1905/1911

Bosnian Crisis (1908) 

assasination of the archduke of Austria-Hungary Franz Ferdinand (June 1914) 

July Crisis (1914)