This summer, events around the world are being held to commemorate 100th anniversary of the beginning of World War I.

One of the most tragic elements of the War to End All Wars is no one power seemed to really want it or be able to do anything to avoid it. Instead, the war began from a seemingly mechanized unraveling of diplomatic relations, with bellicose decisions toppling down the archaic command lines of powers still rooted in an old but rapidly changing world.

And so, the long month from the Assassination of Archduke Franz Ferdinand in Sarajevo to Germany’s invasion of Belgium is one of the most complicated but essential months in human history, so let’s try to get to the bottom of how everything went so wrong.