On September 1 1939 Nazi Germany invaded Poland followed two days later by France and the United Kingdom declaring war on Germany and beginning the Second World War. This was the opening act in what would be the most devastating clash in human history. By its end Europe and much of Asia lay in ruins, tens of millions of people had been killed, wounded or displaced and the world order had been irrevocably altered. But, how did it start? In this episode, Dan delivers one of his monologues on how and why the Second World War came about. He examines both the immediate triggers and the big substructural forces that impelled humanity into another devastating conflict that continues to shape our world today.