World War I, the first 'total war' in history, set in motion profound changes in the economies, demographics, and philosophies of the warring states. In this book, leading experts on the Great War discuss its causes, character, and legacy. Their writings show that to study World War I is to encounter not only the dissolution of the four defeated empires-Russia, Germany, Austria-Hungary, and Turkey-but also the collapse of the optimistic assumption of progress that had defined the nineteenth century.