What was the main cause og worldwar1?

The immediate cause of World War I that made the aforementioned items come into play (alliances, imperialism, militarism, and nationalism) was the assassination of Archduke Franz Ferdinand of Austria-Hungary. In June 1914, a Serbian-nationalist terrorist group called the Black Hand sent groups to assassinate the Archduke.

this isn't a question and if you're going to list things be kind and use commas.

with my recent question