Nearly fourteen million people died during the First World War. But why, and for what reason? Already many contemporaries saw the Great War as a "pointless carnage" (Pope Benedict XV, 1917). Was there a point, at least in the eyes of the political and military decision makers? How did they justify the losses, and why did they not try to end the war earlier? In this volume twelve international specialists analyses and compares the hopes and expectations of the political and military leaders of the main belligerent countries and of their respective societies. It shows that the war aims adopted during the First World War were not, for the most part, the cause of the conflict, but a reaction to it, an attempt to give the tragedy a purpose - even if the consequence was to oblige the belligerents to go on fighting until victory. The volume tries to explain why - and for what - the contemporaries thought that they had to fight the Great War.