\ ~p. \ of such a great source of power, they would certainly require assurances that they would be safeguarded against attack by a state that had secretly violated its promises, This is the well-knowm"safeguards" problem and it is probably the most difficult one which the atomic energy commission will have to face, It is in fact a very old problem. The Greeks knew about it, and their system of hostages was in effect a means of assuring fulfillment of treaty terms beyond the mere promise of the signatories.t A safeguard of almost equal antiquity was the oath. This was particularly prevalent in the Middle Ages when spiritual religious faith was strong and the/supremacy of the Pope over all sovereigns was universally admitted. The conclusion of treaties was marked by religious cere- monies and the taking of the oath, the potential violator beingthreatenedwith major excommunication. There is no doubt about the fact that this added con- this safeguard lost its power, due partly to a diminution aie Oy siderable strength to the sense of obligation of the~signatories. But eventually f faith, partly to a the changed position of the state in reference to the“tffurch, but perhaps chiefly to the fact that it was not really reliable since the person under oath might possibly be absolved from it.¢ Nevertheless, the custom has continued dow to the present day of using terms of religious significance to give as much weight as possible to treaty obligations, for example, "the sanctity of. treaties," "solemn covenants solemnly arrived at," "sacred obligations," etc, ‘Other forms of safeguards used today are the occupation of territory, as in the case of the Rhineland after the First World War, the guarantee by third powers of the fulfillment of a treaty, and the pledging of certain sources of e i. This custom continued down to fairly recent times, the last well-known case being that of the Treaty of Aix-la-Chapellc, October 18, 1748, which pro- vided that two English lords were to be handed over to France until the restoration of Cape Breton Island and the English conquests in the East and West Indies. See Coleman Phillipson, Termination of War and Treaties of Peace, London, 1916, p. 208. 2. See P. C. Borda, De 1l'inexécution des Traités, Paris, 1922, pp. 37-38.