The Prohibition of Biological Weapons – a Norm of Customary International Law?

Like many other dis­armament agreements, the Biological Weapons Convention (BWC) is in crisis. This limits the scope for action for member states and reduces the effec­tive­ness of treaty-based biological weapons control. To maintain and strengthen biological dis­armament, it is therefore necessary to identify options also beyond the BWC and international treaty law. The project aims to contribute to such research by analyzing whether customary international law holds opportunities to strengthen biological weapons control – or, more precisely: whether a customary norm exists against the possession of biological weapons.

To achieve this, the existing state practice regarding biological weapons pos­ses­sion will be system­atically analysed and documented. Using inter alia computer-based qualitative content analysis, it will also be explored whether a pertinent opinio juris can be identified. By addressing the prohibition of biological weapons from a customary law perspective, the project adds a new angle to biological dis­armament research. It can also contribute empirical findings to the international legal discourse on the determination of customary rules and to the debate about the political relevance of customary international law. The project is expected to yield insights regarding the following questions: whether there exists a customary norm regarding the possession of biological weapons, whether such a norm could contribute to strengthening biological weapons control and, more generally, whether customary international law provides opportunities to strengthen multilateral arms control.