Silence within the Process of Normative Change and Evolution of the Prohibition on the Use of Force Normative Volatility and Legislative Responsibility

Abstract

Focusing on the operations of the ‘Global Coalition against ISIL’ in Syria, this article examines whether the mere silence of states in view of state actions that challenge the established reading of Arts. 2(4) and 51 of the UN Charter might induce and consolidate a process of normative change, and if so, under what conditions. While a ‘legislative responsibility’ is incumbent on states in situations of ‘normative volatility’, which requires them to ‘speak up’, I submit that silent behaviour generates norm-evolutionary effects only under strict conditions. Such effects occur if other states and the international community can legitimately expect that a state makes its dissenting position known. The determination of such an expectation requires an overall assessment of numerous factors including: the determinacy of the legality claims made by the acting states, the capacity of silent states to act, the specific circumstances in which a claim was made, the determinacy of reactive claims of other actors, and questions of time, as well as the nature of the affected rules. I conclude by finding that mere passivity in light of the legality-claims currently made with regard to Coalition airstrikes against ISIL positions in Syria does not amount to ‘acquiescence’.