The forces which have brought about the economic futility of military power have also rendered it futile as a means of enforcing a nation's moral ideals or imposing social institutions upon a conquered people. Germany could not turn Canada or Australia into German colonies--_i.e._, stamp out their language, law, literature, traditions, etc.--by "capturing" them. The necessary security in their material possessions enjoyed by the inhabitants of such conquered provinces, quick inter-communication by a cheap press, widely-read literature, enable even small communities to become articulate and effectively to defend their special social or moral possessions, even when military conquest has been complete. The fight for ideals can no longer take the form of fight between nations, because the lines of division on moral questions are within the nations themselves and intersect the political frontiers. There is no modern State which is completely Catholic or Protestant, or liberal or autocratic, or aristocratic or democratic, or socialist or individualist; the moral and spiritual struggles of the modern world go on between citizens of the same State in unconscious intellectual co-operation with corresponding groups in other States, not between the public powers of rival States. This classification by strata involves necessarily a redirection of human pugnacity, based rather on the rivalry of classes and interests than on State divisions. War has no longer the justification that it makes for the survival of the fittest; it involves the survival of the less fit. The idea that the struggle between nations is a part of the evolutionary law of man's advance involves a profound misreading of the biological analogy. The warlike nations do not inherit the earth; they represent the decaying human element. The diminishing rôle of physical force in all spheres of human activity carries with it profound psychological modifications. These tendencies, mainly the outcome of purely modern conditions (_e.g._ rapidity of communication), have rendered the problems of modern international politics profoundly and essentially different from the ancient; yet our ideas are still dominated by the principles and axioms, images and terminology of the bygone days. The author urges that these little-recognized facts may be utilized for the solution of the armament difficulty on at present untried lines--by such modification of opinion in Europe that much of the present motive to aggression will cease to be operative, and by thus diminishing the risk of attack, diminishing to the same extent the need for defence. He shows how such a political reformation is within the scope of practical politics, and the methods which should be employed to bring it about. CONTENTS PART I THE ECONOMICS OF THE CASE