1. See the Charter of the United Nations, Arts. 2(4), 39, 42 and 51. For a typical example of the Security Council authorising the use of feree, see UN Doc. S/678(1990), 29 November 1990. Already under the 1928 Kellogg-Briand Pact (Treaty for the Renunciation of War as an Instrument of National Policy), the existence of the right of individual and collective self-defence was not disputed, as was made explicit in the 1934 Budapest Articles of Interpretation, see M. Hudson, ‘The Budapest Resolutions of 1934 on the Briand-Kellogg Pact of Paris’, 20 AJIL (1935) p. 92.
2. Arts. 24 and 25 of the UN Charter, respectively, require the Council to act in accordance with the Purposes and Principles of the Charter and the Member States to carry out the decisions of the Council in accordance with the Charter.
3. The collective security system of the United Nations (UN) Charter, the humanitarian laws of war, as well as the law of arms control all set rules regarding the employment of armed force by states. These interrelated branches of law can be considered as sub-areas of the ‘international law of military security’, see E. Myjer, ‘The settlement of disputes under the Chemical Weapons Convention and the case of the confidentiality commission’, in D. Bardonnet, ed., The Convention on the Prohibition and Elimination of Chemical Weapons: A Breakthrough in Multilateral Disarmament (Dordrecht, Martinus Nijhoff 1995) pp. 537 at 547.
4. For a detailed survey, see D. Fahey, Chapter 1 of this book.
5. The 1648 Treaty of Westphalia is generally taken as the starting point of the creation of the modern international system composed of sovereign states, see, for example, L. Gross, ‘The peace of Westphalia, 1648–1948’, 42 AJIL (1948) p. 20. Long before that, rulers experienced difficulties in safeguarding their security; witness the many pacts and alliances, arms control treaties and peace treaties that were concluded as early as 3100 BC. For a historical overview, see A. Nussbaum, A Concise History of the Law of Nations (New York, McMillan 1961); T. Dupuy and G. Hammerman, eds., A Documentary History of Arms Control and Disarmament (New York, Bowker 1973).