Discussions on the allocation of international responsibility between an international organization and its member states do not comprehensively engage with the role of obligations in assigning responsibility to the organization and/or its members. The present article sets out what will be termed an obligations-based approach to the allocation of international responsibility by exploring the phenomenon of sharing international obligations by an international organization and its members, as well as the implications thereof for their responsibility under international law. It will do so by focusing on the practice of concluding mixed agreements by the EU and its member states, which commonly results in overlapping obligations for the organization and its members. It is ultimately argued that a distinction should be made between two types of shared obligations in mixed agreements in order to untangle who can be held responsible in case of a breach: the EU, the member state(s), or both.

国际组织与其成员国之间关于国际责任分配的讨论并未全面涉及义务在向该组织和/或其成员分配责任方面的作用。本文通过探讨国际组织及其成员分担国际义务的现象及其对国际法规定的责任的影响，阐述了所谓的基于义务的国际责任分配方法。它将通过关注欧盟及其成员国缔结混合协议的做法来做到这一点，这通常会导致该组织及其成员承担重叠的义务。