The Philosophy of Law: Public Right, § 61: Perpetual Peace and a Permanent Congress of Nations
The natural state of Nations as well as of individual men is a state which it is a duty to pass out of, in order to enter into a legal state. Hence, before this transition occurs, all the Right of Nations and all the external property of States acquirable or maintainable by war, are merely provisory; and they can only become peremptory in a universal Union of States analogous to that by which a Nation becomes a State. It is thus only that a real state of Peace could be established. But with the too great extension of such a Union of States over vast regions any government of it, and consequently the protection of its individual members, must at last become impossible; and thus a multitude of such corporations would again bring round a state of war. Hence the Perpetual Peace, which is the ultimate end of all the Right of Nations, becomes in fact an impracticable idea. The political principles, however, which aim at such an end, and which enjoin the formation of such unions among the States as may promote a continuous approximation to a Perpetual Peace, are not impracticable; they are as practicable as this approximation itself, which is a practical problem involving a duty, and founded upon the Right of individual men and States.
Such a Union of States, in order to maintain Peace, may be called a Permanent Congress of Nations; and it is free to every neighbouring State to join in it. A union of this kind, so far at least as regards the formalities of the Right of Nations in respect of the preservation of peace, was presented in the first half of this century, in the Assembly of the States-General at the Hague. In this Assembly most of the European Courts, and even the smallest Republics, brought forward their complaints about the hostilities which were carried on by the one against the other. Thus the whole of Europe appeared like a single Federated State, accepted as Umpire by the several nations in their public differences. But in place of this agreement, the Right of Nations afterwards survived only in books; it disappeared from the cabinets, or, after force had been already used, it was relegated in the form of theoretical deductions to the obscurity of Archives.
By such a Congress is here meant only a voluntary combination of different States that would be dissoluble at any time, and not such a union as is embodied in the United States of America, founded upon a political constitution, and therefore indissoluble. It is only by a Congress of this kind that the idea of a Public Right of Nations can be established, and that the settlement of their differences by the mode of a civil process, and not by the barbarous means of war, can be realized.