Non-State Sanctions: Private Instruments of International Law

By: Ali Hakim & Matei Alexianu

PDF: Non-State Sanctions

Amid the catastrophic wars in Gaza and Ukraine, private organizations have arranged boycotts, bans, and other nonviolent measures to pressure Israel and Russia to comply with international law. These are just the latest examples of a long tradition of international law enforcement by non-state actors. But despite this rich history, international law doctrine and discourse understand sanctions exclusively as tools of states and multilateral organizations. This Article documents and analyzes the role of sanctions imposed by non-state actors in shaping and enforcing international law across a variety of domains, including self-determination, human rights, humanitarian law, and environmental law.

The Article begins by introducing the concept of non-state sanctions into the international legal lexicon. It contends that sanctions are best understood as coercive, nonmilitary measures deployed to bring states, groups, or individuals into compliance with international law. This definition naturally encompasses actions by non-state actors. After defining non-state sanctions, we map out the process of imposing such measures, which involves not only the enforcement activities themselves but also upstream fact finding and legal interpretation.

Next, we classify non-state sanctions, providing examples of the practice’s central role in historical and contemporary legal controversies. The cases we highlight fall into four categories, which mirror the types of sanctions that states commonly deploy: trade restrictions, denials of privilege, asset restrictions, and cyber operations. Examples include the boycott and divestment movements against Israel and South Africa; bans by international sporting and cultural institutions; seizures of private property by anti-colonial movements and non-state armed groups in India, Kenya, and Nigeria; and “hacktivist” cyber operations against China, Tunisia, and Turkey.

Finally, the Article unpacks the normative implications of non- state sanctions. Like any coercive exercise, they are a mixed bag, and their effects on legal compliance and the coherence of the international system vary from case to case. On the one hand, non-state sanctions can help enforce international law—particularly where states are unable or unwilling to act—and empower marginalized groups to contribute to the development of international norms. On the other hand, these measures risk harming innocent individuals, eroding the sovereignty of Third World states, and undermining the predictability and coherence of international law. Reckoning with these potential benefits and pitfalls is crucial for determining how non-state sanctions can most effectively contribute to international justice and peace. By making the practice legible in the language of international law, this Article urges an overdue conversation about how non-state sanctions should be integrated into the global legal architecture.