The Concept of Self-Defence Against Non-State Actors: The ICJ’s Decision in Armed Activities on the Territory of the Congo (Democratic Republic of the Congo v. Uganda)

The right of self-defence is a fundamental principle of international law recognised under Article 51 of the Charter of the United Nations. Its application is relatively settled where one state is subjected to an armed attack attributable to another state. Considerable controversy nevertheless remains where armed attacks are conducted by non-state actors operating from the territory of another state without clear attribution to that state. This article examines the concept of self-defence against non-state actors through the International Court of Justice's decision in Armed Activities on the Territory of the Congo (Democratic Republic of the Congo v. Uganda). Using a qualitative doctrinal approach, the article analyses the Court's treatment of consent, use of force, Uganda's invocation of self-defence, belligerent occupation, violations of international humanitarian and human rights law, and exploitation of natural resources. Particular attention is given to the Court's decision not to determine whether large-scale attacks by independent non-state actors can, by themselves, trigger the right of self-defence under Article 51. The article argues that although the Court correctly rejected Uganda's claim on the evidence before it, its restrictive and cautious approach left an important doctrinal question unresolved. In light of contemporary security threats posed by transnational armed groups, greater judicial clarification is needed on the circumstances in which a victim state may lawfully respond to a non-state actor operating from another state's territory while respecting the host state's territorial sovereignty.