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.
