Proportionality Balancing under General International Law: the Case of Article 25(1)(b) of ARSIWA

Abstract

Abstract Article 25(1)(b) of ARSIWA provides that a plea of necessity defence must not seriously impair an essential interest of the State or States towards which the obligation exists, or of the international community as a whole. This requires a balancing between the interest of the invoking State and that of the victim State or the international community. However, how to conduct such a balancing has not been adequately addressed in practice on in literature. This article adopts the approach of proportionality balancing under domestic public law and certain branches of international law and applies it to the context of Article 25(1)(b). Specifically, this article draws from the principle of balancing by Robert Alexy, who advocates balancing not the interests per se, but the change in respective interests caused by the intervening event. This article argues that such an approach avoids the value judgments that should be reserved for States and provides for a workable solution to operationalize Article 25(1)(b). Through a critical review of judicial and arbitral decisions, this article further explores how such an approach to proportionality balancing may be applied in the context of Article 25(1)(b) in practice, which can be broken down to three balancing pairs, depending on the party against which the necessity plea is invoked: State versus State, individual versus State, and State versus international community.