World War I

"Few events are more central to the history of the 20th century than the First World War.  Without Sarajevo, Tannenberg and the Somme, we have no Hitler, no Lenin, no Hemingway.  The history of the past hundred years flows directly from the happenstance series of events that led to Europe destroying itself for little reason between 1914 and 1918."

The whole piece can be found on Pieria.