The real difficulty, therefore, turns upon the agreement upon a basis of comparative expenditure. Now this difficulty appears insuperable, if reduction of armaments be regarded as the sole, or the chief, mainstay of a durable peace. For so long as the motives which have hitherto impelled nations to increase their armaments still retain the appearance of validity in any nation or group of nations, no agreed basis for reduction will be reached, or, were it reached, no reliable adherence to its terms could be expected. For the reduction of armaments involves the acceptance of and the adherence to a principle of reduction by all the Great Powers. If any single Great Power refused to come into the agreement, or, coming in, was suspected of evading the fulfilment of its pledge by concealing some of its expenditure on armaments, this method would have failed _pro tanto_, both as an economy and a security. For each of the would-be pacific nations would have to make adequate provision against the warlike outsider or suspect. Now, that a mere agreement for mutual disarmament would thus be baffled is almost certain. So long as a Power, by simply refusing to come in, could retain full liberty to pile up arms with a view to a future policy of menace or aggression, would there not be Governments which would find some more or less plausible excuses for declining the invitation to come in? Or could we feel complete assurance that a Power with an aggressive past, after entering into such an agreement, would faithfully fulfil it when so many facilities of evasion present themselves? Nay, there would be a positive incentive to an aggressive or revengeful Power either to stay outside, or, entering in, to violate secretly its obligations. For, by either course, it would be enabled to steal a march in military strength over its intended enemy, if the latter were a faithful adherent to such a treaty. The slightest reflection suffices to show that a mere agreement for disarmament or reduction of armament must be futile. But, it will be contended, these difficulties may be overcome by extending the agreement so as to bind the signatory Powers to bring their united force to bear upon any member convicted of a wilful evasion or infraction of the agreement. That is to say, they must engage to secure the agreement by an ultimate sanction of physical force. The administration of such an agreement would, of course, involve the setting up of some standing Court or Committee of Inquiry, vested with full rights of inspection and judgment, and endowed with a power of armed executive.