As, under Article 10 of the Protocol, it may happen that both States involved in a dispute are declared to be aggressors, the question arose as to what would be the best method of settling this problem. There were three alternatives: to apply the principle contained in paragraph 1, which is practically equivalent to making a sort of police war on both parties--or to leave the matter to pursue its course, or, finally, to compel States which disturb the peace of the world to desist from acts of war by the employment of means less severe than those indicated in paragraph 1. It is the last method which has been chosen. Only economic measures will be taken against such States, and naturally they will not be entitled to receive the assistance referred to in Article 11, paragraph 3. {203} _Article 12._ Article 16, paragraph 1, of the Covenant provides for the immediate severance of all trade or financial relations with the aggressor State, and paragraph 3 of the same Article provides, _inter alia_, for economic and financial co-operation between the State attacked and the various States coming to its assistance. As has already been pointed out, these engagements have been confirmed and made more definite in Article 11 of the Protocol. But the severance of relations and the co-operation referred to necessarily involve measures so complex that, when the moment arises, doubts may well occur as to what measures are necessary and appropriate to give effect to the obligations assumed under the above provisions. These problems require full consideration in order that States may know beforehand what their attitude should be. Article 12 defines the conditions of such investigation. It is not expressly stated that the problem will be examined by the Council in collaboration with the various Governments, but the Council will naturally, if it deems it necessary, invite the Governments to furnish such information as it may require for the purpose of carrying out the task entrusted to it under Article 12. _Article 13, paragraph 1._ The above explanation of Article 11, paragraphs 1 and 2, contains many references to Article 13. As I have already pointed out, in case sanctions have to be applied, it is highly important that there should exist some organ competent to express an opinion as to the best way in which their obligations could be carried out by the signatories. As you are aware, this organ, according to the Covenant, is the Council. In order that the Council may effectively fulfil this duty, Article 13 empowers it to receive undertakings from States, determining _in advance_ the military, naval and air forces which they would {204} be able to bring into action immediately in order to ensure the fulfilment of the obligations in regard to sanctions arising, out of the Covenant and the present Protocol.