Austritt und Ausschluss aus Internationalen Organisationen – Zwischen staatlicher Souveränität und zwischenstaatlicher Kooperation

Withdrawal and expulsion from international organizations raise fundamental questions concerning the legitimacy and raison d'être of the organization in question. Whilst the variety of international treaty provisions on withdrawal and expulsion is enormous, some treaties do not address these questions at all. The ensuing regulatory complexity calls for a systematic framing of withdrawal and expulsion. In order to determine their lawfulness, it is therefore essential to focus on the interests that lead to withdrawal and expulsion in the first place: inter-state cooperation as a fundamental characteristic of every international organisation on the one hand and enduring claims of state sovereignty on the other. This article shows that a right to withdrawal is in principle in line with these underlying interests of the organisation and the member state. Withdrawal can, however, be conditioned to ensure the continued viability of the organisation. Expulsion, by contrast, is in principle incompatible with these interests and can only be used as a last resort, if the functioning of the organisation would otherwise be impaired. The constitutive treaties of international organisations largely reflect these assumptions. Those constitutive treaties that remain silent on the issue of withdrawal or expulsion can likewise be interpreted in accordance with the Vienna Convention on the Law of Treaties by using the yardstick of the decisive interests of inter-state cooperation and state sovereignty, respectively.This theoretical discussion is complemented by an overview of practice in the grey area between active membership and termination of membership. Forms of inactive membership that are not provided for in treaty law demand for clear rules on withdrawal and expulsion reflecting the underlying interests of the international organisation and its members. In view of the foregoing analysis, the last part of the article focuses on the legal and political consequences of withdrawal and expulsion from an international organisation.