Attribution of Non-State Actor Conduct During Armed Conflict

Abstract Armed conflict today involves a plethora of non-State actors, including armed groups, private military companies, and hackers operating in the cyber domain. Frequently, these non-State actors cause harm to civilians or otherwise act in a manner that could violate international law, and they commonly act with the benefit of some form of State support. This book explores when non-State actor conduct during armed conflict is attributable to a State, potentially leading to that State’s international responsibility. Using the conflicts in Syria, Ukraine, and the Democratic Republic of the Congo as case studies, the book seeks to clarify the meaning and practical application of the six rules of attribution reflected in the International Law Commission’s Articles on State Responsibility in the context of armed conflict. It examines each of the rules in turn, using examples from the case studies to demonstrate when the rules would apply to attribute non-State actor conduct to a State. As part of the analysis, the book evaluates the effectiveness of each rule in holding States to account for non-State actor conduct performed on their behalf. Concluding that there is an accountability gap that allows States to act via proxy in a manner they could not lawfully operate through their own State organs, the book also assesses how the inadequacies in the regulation of States’ support to non-State actors in conflict situations should be remedied.