The Covenant of the League of Nations erected a wall of protection around the peace of the world, but it was a first attempt {165} at international organisation and it did not succeed in closing the circle sufficiently thoroughly to leave no opening for war. It reduced the number of possible wars. It did not condemn them all. There were some which it was forced to tolerate. Consequently, there remained, in the system which it established, numerous fissures, which constituted a grave danger to peace. The new system of the Protocol goes further. It closes the circle drawn by the Covenant; it prohibits all wars of aggression. Henceforth no purely private war between nations will be tolerated. This result is obtained by strengthening the pacific methods of procedure laid down in the Covenant. The Protocol completes them and extends them to all international disputes without exception, by making arbitration compulsory. In reality, the word "arbitration" is used here in a somewhat different sense from that which it has generally had up to now. It does not exactly correspond with the definition given by the Hague Conferences which, codifying a century-old custom, saw in it "the settlement of disputes between States by judges of their own choice and on the basis of respect for law" (Article 37 of the Convention of October 18th, 1907, for the Pacific Settlement of International Disputes). The arbitration which is now contemplated differs from this classic arbitration in various respects: (_a_) It is only part of a great machinery of pacific settlement. It is set up under the auspices and direction of the Council of the League of Nations. (_b_) It is not only an instrument for the administration of justice. It is, in addition and above all, an instrument of peace. The arbitrators must no doubt seek in the first place to apply the rules and principles of international law. This is the reason why, as will be seen below, they are bound to consult the Permanent Court of International Justice if one of the parties so requests. But if international law furnishes no rule or principle applicable to the particular {166} case, they cannot, like ordinary arbitrators, refuse to give a decision. They are bound to proceed on grounds of equity, for in our system arbitration is always of necessity to lead to a definitive solution of the dispute. This is not to be regretted, for to ensure the respect of law by nations it is necessary first that they should be assured of peace,