World War One.

THE NATURE OF WORLD WAR 1 'The military mind always imagines that the next war will be on the same lines as the last. That has never been the case and never will be.' (Foch, 1926) No one had expected the First World War to become the "War to end all wars" as it was hailed at its conclusion. The general consensus in early 1914 was that it would all be over by Christmas of that year. …

…not one nation on earth that had in mind the notion to wage war, times soon changed yet again, bringing with them further advances, new weapons and new methods of killing people by the thousands. In 1939, World War Two had begun, and proved to be even more costly than its previous incarnation, with the greatest toll being on the civilians. It seems people never change, but their ways of killing each other never cease development.