Secondly, they must reserve force for the coercion of the law-breaker; and that implies that they should construct rules to determine who the law-breaker is.  Let him be defined as the one who appeals to force, instead of appealing to law and right by machinery duly provided for that purpose, and the aggressor is immediately under the ban of the civilized world, and met by an overwhelming force to coerce him into order.  In constructing machinery of this kind there is no intellectual difficulty greater than that which has confronted every attempt everywhere to substitute order for force.  The difficulty is moral, and lies in the habits, passions, and wills of men.  But it should not be concluded that, if such a moral change could be operated, there would be no need for the machinery.  It would be as reasonable to say that Governments, law-courts, and police were superfluous, since, if men were good, they would not require them, and if they are bad they will not tolerate them.  Whatever new need, desire, and conviction comes up in mankind, needs embodiment in forms before it can become operative.  And, as the separate colonies of America could not effectively unite until they had formed a Constitution, so will the States of Europe and the world be unable to maintain the peace, even though all of them should wish to maintain it, unless they will construct some kind of machinery for settling their disputes and organizing their common purposes, and will back that machinery by force.  If they will do that they may construct a real and effective counterpoise to aggression from any Power in the future.  If they will not do it, their precautions against any one Power will be idle, for it will be from some other Power that the danger will come.  I put it to the reader at the end of this study, which I have made with all the candour and all the honesty at my disposal, and which I believe to represent essentially the truth, whether or no he agrees that the European anarchy is the real cause of European wars, and if he does, whether he is ready for his part to support a serious effort to end it.