If, for example, one State alleges that another State is engaged in preparations which are nothing less than a particular form of threat of war (such as any kind of secret mobilisation, concentration of troops, formation of armed bodies with the connivance of the Government, etc.), the Council, having established that there is a case for consideration, will apply the procedure which may be defined as the procedure of preventive measures; it will arrange for suitable enquiries and investigations, and, in the event of any breach of the provisions of paragraph 1 being established, will take the steps described in Article 7, paragraph 4. 3.--SECURITY--SANCTIONS. _Article 11._ (_Article 11, paragraphs 1 and 2, of the Protocol in its relation to Articles 10 and 16 of the Covenant_) According to Article 10 of the Covenant, Members of the League undertake to preserve as against external aggression the territorial integrity and existing political independence of all Members of the League. In case of aggression, the Council shall advise upon the means by which this obligation shall be fulfilled. According to Article 16, should any Member of the League resort to war in disregard of its engagements under Articles 12, 13 or 15, all other Members of the League undertake immediately to apply economic sanctions; furthermore, it shall be the duty of the Council to recommend to the several Governments concerned what effective military, naval or air forces the Members of the League shall severally contribute to the armed forces to be used to protect the engagements of the League. {198} At the time when they were drafted at the Peace Conference in Paris in 1919, these articles gave rise to keen controversy as to the exact scope of the engagements entered into in these provisions, that is to say, as to the nature and extent of the obligations referred to in Article 10, the exact moment at which such obligations arose, and the legal consequences of the Council recommendations referred to in Article 16, paragraph 2. This controversy continued, as is well known, in the debates here in Geneva, where the question has been discussed in previous years. Article 11 is intended to settle this controversy. The signatories of the present Protocol accept the obligation to apply against the aggressor the various sanctions laid down in the Covenant, as interpreted in Article 11 of the Protocol, when an act of aggression has been established and the Council has called upon the signatory States immediately to apply such sanctions (Article 10, last paragraph). Should they fail so to do, they will not be fulfilling their obligations.