Russia found herself in a condition of acute social instability, momentarily threatened by the event which in 1917 cast her beyond the pale of western civilization. To Russia the war came as a happening which could dissipate the revolutionary ferments, mobilize her refractory workers into the army, and, through the tremendous appeal of a national crusade, sidetrack the forces of anarchy in precisely the way that those forces were sidetracked in Ireland in 1914. Had the war been won quickly――as there were grounds for hoping when it began――the Czar would probably still be on the throne of an enlarged and yet more powerful Russia. By the events of the last hundred years Germany had been elevated from a position of relative unimportance to that of the most highly organized and perfectly industrialized power in the world. In achieving this promotion she had earned the venomous hatred, born of her humiliation, of France, and the slowly growing, disquieting suspicion of Great Britain. Conscious of her growing industrial strength, becoming restive within the frontiers which confined her swelling population, aware of the hostility of her neighbours, and never allowed to forget that her kingdom had been built upon the sword, the youthful soul of Germany found, in her Emperor, a fitting symbol for her aspirations. He was the creation of her mood, and together with the party of which he was the mouthpiece led her to her downfall. It would not be a fair statement to assert that population pressure in Germany was the cause of the war. It was unquestionably a part-cause and a predisposing cause, as it was of migration in prehistoric times and of most wars since. But it was here complicated by other factors both inside and outside Germany. The universal desire to avert a similar catastrophe in the future has materialized in the League of Nations. It is hoped that through its agency many precipitating causes of war will be eliminated. By it provocation will be made more difficult and commitment more perilous. But the essential predisposing cause, that of over-multiplication, remains unassailed. Like some dull-witted monster it is left to wax in strength and malignancy within its fetters, till at last, no longer to be denied, it will break all bounds, turn, and rend the world. From the late war no lesson as to the importance of population control has been learnt. Will another war be necessary to teach us this lesson?