Unilateral extraterritorial sanctions: between legal justification and jurisdictional overreach

Details

Supervisors

Radi, Yannick

Faculty

Faculté de droit et de criminologie

Degree label

Master [120] en droit, à finalité spécialisée: Droit transnational, comparé et étranger

Abstract

This thesis explores the legality of unilateral extraterritorial sanctions within the framework of international law. Although sanctions have historically served as instruments of foreign policy, their application to govern actions beyond the territory of the sanctioning state, often pressuring third-country nationals to adhere, introduces legal ambiguity. The research begins by reviewing the UN Charter framework, which assigns the authority for coercive measures primarily to the Security Council, followed by an analysis of jurisdictional foundations in customary law and limitations such as proportionality, necessity, and non-discrimination. Utilising case law and state practices, it investigates the boundaries of lawful extraterritorial actions. A comparative examination of the sanctions regimes of the U.S. and the EU reveals contrasting methodologies: the United States frequently implements extensive secondary sanctions while the European Union generally opposes extraterritoriality, as demonstrated by its Blocking Statute. The thesis concludes that while some unilateral sanctions may be defensible, expansive secondary sanctions remain difficult to reconcile with sovereignty, non-intervention, and the coherence of international law.