To share or not to share? The allocation of responsibility between international organizations and their member states

This article discusses the costs and benefits of sharing responsibility between states and international organizations for their own internationally wrongful acts. The emphasis of the law of international responsibility lies on exclusive responsibility. As discussed in Part 1 of this article on the attribution of wrongfulness to states and international organizations, strong reasons speak in favor of emphasizing the independence of the responsible actors. By distinguishing wrongfulness from responsibility, however, it will be argued in Part 2 that independent wrongful acts will not necessarily lead to exclusive responsibility. A number of recent cases involving military operations have illustrated that shared responsibility is a frequent outcome of the cooperation between states and international organizations. Nonetheless, such shared responsibility seems to come with more costs than benefits. Injured parties, in particular, are often left without a remedy when potential wrongdoers shift the buck of responsibility between them. In order to reduce the costs of shared responsibility of states and international organizations, this article therefore advocates for the recognition of a principle of joint and several responsibility in international law, which would allow for the balancing of the different interests of injured and responsible parties.