If both parties to the dispute, when so invited, refuse to accept the obligations of membership in the League for the purpose of such dispute, the Executive Council may take such action and make such recommendations as will prevent hostilities and will result in the settlement of the dispute. [Sidenote: Supervision of trade in arms.] ART. XVIII.--The high contracting parties agree that the League shall be intrusted with general supervision of the trade in arms and ammunition with the countries in which the control of this traffic is necessary in the common interest. [Sidenote: Development of backward peoples a sacred trust.] ART. XIX.--To those colonies and territories which, as a consequence of the late war, have ceased to be under the sovereignty of the States which formerly governed them and which are inhabited by peoples not yet able to stand by themselves under the strenuous conditions of the modern world, there should be applied the principle that the well-being and development of such peoples form a sacred trust of civilization and that securities for the performance of this trust should be embodied in the constitution of the League. The best method of giving practical effect to this principle is that the tutelage of such peoples should be intrusted to advanced nations, who by reason of their resources, their experience, or their geographical position, can best undertake this responsibility, and that this tutelage should be exercised by them as mandatories on behalf of the League. The character of the mandate must differ according to the stage of the development of the people, the geographical situation of the territory, its economic conditions and other similar circumstances. [Sidenote: Provisional recognition of certain communities.] Certain communities, formerly belonging to the Turkish Empire, have reached a stage of development where their existence as independent nations can be provisionally recognized, subject to the rendering of administrative advice and assistance by a mandatory power until such time as they are able to stand alone. The wishes of these communities must be a principal consideration in the selection of the mandatory power. [Sidenote: Central Africa peoples.] Other peoples, especially those of Central Africa, are at such a stage that the mandatory must be responsible for the administration of the territory, subject to conditions which will guarantee freedom of conscience or religion, subject only to the maintenance of public order and morals, the prohibition of abuses such as the slave trade, the arms traffic, and the liquor traffic, and the prevention of the establishment of fortifications or military and naval bases and of military training of the natives for other than police purposes and the defense of territory, and will also secure equal opportunities for the trade and commerce of other members of the League. [Sidenote: The South Pacific Isles.]