This chapter starts from the premise that secondary sanctions are invariably adopted to exert pressure upon foreign economic or financial actors operating in third states, with the intention to modify their conduct in alignment with the primary sanctions already imposed by the sanctioning state against the target state. As follows, due to their extraterritorial scope and their exceptional capacity to encroach upon the sovereignty of other countries, the legal status of secondary sanctions under international law is controversial. This contribution seeks to elucidate if secondary sanctions may amount to economic coercion and whether as a result these measures could constitute a breach to the principle of non-intervention. The chapter closes by exploring the potential avenues for regime interaction between the rules governing the exercise of jurisdiction by states and the principle of non-intervention in the context of secondary sanctions.

The growing range and changing nature of unilateral sanctions have seen the emergence of a new label of so-called ‘secondary’ sanctions, as opposed to the more traditional ‘primary’ sanctions. While there is no accepted legal definition of secondary sanctions, in essence, secondary sanctions restrict economic transactions between third countries which may be entirely lawful under the law of these countries. Their extraterritorial character gives secondary sanctions their distinctive and particularly controversial character. Secondary sanctions create inter-State tension and may possibly violate a number of public international law regimes. They may harm the politico-economic interests of third States and cause headaches for private economic operators, whose potential exposure to secondary sanctions complicates the already complex web of multi-jurisdictional norms governing their international business transactions.

This chapter explores how the imposition of unprecedented sanctions against Russia following the large-scale invasion of Ukraine in 2022 and the constant cat-and-mouse game of enforcement and evasion that ensued have altered the secondary sanctions landscape. More specifically, it examines to what extent, notwithstanding its longstanding and entrenched opposition to far-reaching US secondary sanctions, the European Union has gradually moved towards adding a ‘secondary’ layer to its own sanctions toolbox. The chapter first exposes the EU’s ambiguity towards extraterritoriality, both within and without the sanctions domain. It subsequently zooms in on a number of specific EU measures, namely the imposition of the so-called ‘price cap’ on Russian oil, the adoption of far-reaching import and export restrictions, including the prohibition to import certain Russian products even after these are located or have already been processed in third countries, and the threat of financial sanctions against, and criminal prosecution of, non-EU persons that facilitate the circumvention of EU sanctions against Russia. It then offers some concluding observations.