Now such a definite, tangible, practical aim does exist, and seems to justify, and, indeed, to require, the publication of the facts contained in this book and also in the reports which have been published by the Belgian, French, and British Governments. It is an aim which can be stated quite shortly; and the need for pursuing it is shown by what has happened during the last twenty months. In most parts of the ancient world, and among the semi-civilised peoples of Asia till very recent times, wars were waged against combatants and non-combatants alike. Even in the European Middle Ages indiscriminate slaughter of combatants and non-combatants alike sometimes occurred, especially where, as in the case of the Albigenses, religious passion intensified hatred. As late as the sixteenth and seventeenth centuries there were campaigns in which frightful license was allowed to soldiery, private property was pillaged or ruthlessly destroyed, and women were habitually outraged. A reaction of sentiment caused by the horror of the Thirty Years’ War, coupled with a general softening of manners, brought about a change. During the last two centuries, though every war was marked by shocking incidents, there was a growing feeling that non-combatants should be protected, and a serious purpose to restrain the excesses of troops invading a hostile country. The wars of the eighteenth century were less cruel and destructive than those of the seventeenth, and the wars of the nineteenth showed some improvement on those of the eighteenth. The war of 1870-71, if those of us in Britain who remember it can trust our recollection, seemed better in both the above-named respects than had been the Revolutionary and Napoleonic wars between 1793 and 1814. Till the outbreak of the present conflict men who sought for signs of the progress of mankind were cheered by the hope that war would hereafter be waged only between regular disciplined forces on each side; that these forces would abstain from needless cruelty, that women would be protected from lust, and that the lives of non-combatants would not be endangered. There was even a prospect that private property would not be destroyed except in so far as a definite military aim made its destruction unavoidable, as when a hostile force had to be shelled out of its shelter in a village. The Hague Convention had passed rules which ameliorated the practices of war as regards the combatant forces and had solemnly proclaimed the duty of respecting the lives and property of non-combatant civilians.