Are Security Council acts relevant to the formation of Customary International Law?
Just like General Assembly resolutions can be indicative of state practice and opinio juris, I have always assumed that acts of the Security Council – an organ of the UN, composed of states – would be relevant as evidence and to the formation of customary international. Significantly, however, Security Council acts do not feature in the first report of the Special Rapporteur Sir Michael Wood, on the ILC’s current study on the formation of custom. A word search reveals “zero” matches with Security Council, while the General Assembly comes up 13 times. There is no explanation in the report for why Security Council acts are not relevant to custom.
Given the Security Council’s power to legislate, this omission is both interesting and significant. One could surmise it is due to the Council’s composition – its members number 15 – as opposed to the universal membership of the General Assembly. Perhaps its not a big enough cross section, even though the P5 would presumably be big players in determining custom. Or perhaps it is related to the fact that the Council can act inconsistently, not always applying principles consistently in like cases. Further still, perhaps it emanates from distrust of the Council’s occasional role as a legislator. Indeed, if Security Council acts (and as a subsidiary matter, statements of Council members during meetings of the Security Council) are relevant to custom, then those same customary rules would bind the UN (and the Council as an organ of the UN), which raises important considerations with regards to the perennial debate about what legal limits apply to the Security Council.
The Council’s capacity to bind member states, and derivatively International Organizations, under Articles 25 and 48 is well established. Its ability to override inconsistent law under Article 103, and its demonstrated propensity to legislate in areas like anti-terrorism, and the many calls in the mid-2000s for Council power to be curbed through judicial review or other means, would lead one to expect at least consideration of the Council’s role. It is noteworthy that in the Memorandum prepared by the Secretariat’s on the same topic, the Security Council is mentioned twice in relation to non-recognition of acts in breach of peremptory norms (citing the ILC’s commentary on State responsibility, which in turn cites Council resolutions on Iraq’s invasion of Kuwait and the situation in Rhodesia.) I note that Greg Fox and I are interested in the question of Security Council legislation, and are now embarking on an empirical assessment of the Council’s law-making in relation to the field of armed conflict. As a result, I may have a vested interest in the debate… Nonetheless, what do readers think: should Security Council decisions be considered in regards to the formation of customary international law?