All history, and all the present relations of nations to one another may, of course, be considered in terms of the desires for specific objectives caused by the imperial desires of peoples, these desires themselves being regarded as a sum of motives, the effects of past political relations, and containing both rational and irrational elements. The world is a vast field of stress in which the powers at work are national wills rather than political forces as the projects of rulers and the diplomats. These powers, when fully aroused, are quite beyond the control of statesmen acting in their ordinary capacities, and their final issues no historian ought now to try to predict. History has been full of surprises because of the nature of the forces which create history, and these surprises seem to have been sometimes the greatest for those who were most intimately concerned in making history. Events seldom run smoothly according to well laid plans. It would not fall within the scope of a psychological study of war to describe or analyze the complex system of strains that exist in the world to-day, and to point out the conditions that led to the great war would be for the most part unnecessary, since they must be obvious to all. The main items in such a study of history, however, may well be recalled to mind. One would need to show the effects of England's irresistible development through several centuries; the struggle for the control of the Mediterranean; Germany's efforts to extend her empire toward the East, and the closing of doors against Germany's advance; Russia's pressure upon the Teutonic peoples, the ancient and terrible dread of Russia on the part of the nations of Western Europe, the shadow under which Turkey, Germany, and England had lived because of the presence of the great Slavic state, with its mysticism, its dynastic ambitions and its great growth force, its need of open ports, and vital interest in the amalgamation of the South Slavic peoples, and the determination to own Constantinople and to succeed to the place of the Turkish Empire. We should need to take into account the long history of the struggle for colonies, the colonial trust of Russia, England and France, the ambitions of France for empire in Africa, the operations of French finance in the Balkans and elsewhere, Austria's aggressive hatred of Serbia, and her effort to prevent the revival of Poland, the conflicts of Germany and Austria with Italy in regard to the AEgean and the Adriatic and their shores, the fierce irredentism of Italy, and the ambitions of Italy that have brought her into conflict with the Teutonic powers and with Turkey, all the conflicting purposes and ambitions of Greece, Roumania, Bulgaria, and Serbia, and the added strain in the Balkans because of the vital interests of all the Great Powers there, and many other conflicts and causes of conflicts. These conflicts we see repeated in kind in the