War differs from the employment of force by the police through the fact that the actions of the police are ordered by a neutral authority, whereas in war it is the parties to the dispute themselves who set force in motion. This distinction is not absolute, since the State is not always wholly neutral in internal disturbances. When strikers are shot down, the State is taking the side of the rich. When opinions adverse to the existing State are punished, the State is obviously one of the parties to the dispute. And from the suppression of individual opinion up to civil war all gradations are possible. But broadly speaking, force employed according to laws previously laid down by the community as a whole may be distinguished from force employed by one community against another on occasions of which the one community is the sole judge. I have dwelt upon this difference because I do not think the use of force by the police can be wholly eliminated, and I think a similar use of force in international affairs is the best hope of permanent peace. At present, international affairs are regulated by the principle that a nation must not intervene unless its interests are involved: diplomatic usage forbids intervention for the mere maintenance of international law. America may protest when American citizens are drowned by German submarines, but must not protest when no American citizens are involved. The case would be analogous in internal affairs if the police would only interfere with murder when it happened that a policeman had been killed. So long as this principle prevails in the relations of States, the power of neutrals cannot be effectively employed to prevent war. In every civilized country two forces coöperate to produce war. In ordinary times some men—usually a small proportion of the population—are bellicose: they predict war, and obviously are not unhappy in the prospect. So long as war is not imminent, the bulk of the population pay little attention to these men, and do not actively either support or oppose them. But when war begins to seem very near, a war fever seizes hold of people, and those who were already bellicose find themselves enthusiastically supported by all but an insignificant minority. The impulses which inspire war fever are rather different from those which make some men bellicose in ordinary times. Only educated men are likely to be warlike at ordinary times, since they alone are vividly aware of other countries or of the part which their own nation might play in the affairs of the world. But it is only their knowledge, not their nature, that distinguishes them from their more ignorant compatriots. To take the most obvious example, German policy, in recent years before the war, was not averse from war, and not friendly to England. It is worth while to try to understand the state of mind from which this policy sprang.