The chapter of the United Nations Charter that is headed: “Action with respect to threats to the peace, breaches of the peace and acts of aggression” and includes Articles 39–51 of the Charter. Those who devised the UN Charter were acutely aware of the failure of the former Covenant of the League of Nations in respect of collective security, namely (1) that it left it open to member states to respond, or not respond, to the call for military aid and (2) it provided no machinery or system for organizing League forces in advance or for coordinating such responses as members might make. Chapter VII addressed such problems by empowering the Security Council to orchestrate such collective actions under Articles 42 and 43. Under Articles 43–47 advance preparation of collective action was to be made through a Military Staff Committee. Article 51 creates a right to self-defence for member states; controversially, it is held to have preserved the wider scope of self-defence in customary international law. A use of force not brought under Chapter VII of the UN Charter is illegal. The consequences of this can be great when one is assessing the matter of war crimes. See also enforcement action.