Can the EU Maintain Sanctions Against Russia After a Peace Agreement?

[Hryhorii Turshukov is a research associate and teaching assistant at the Institute for European Law and the Leuven Institute of Criminology (LINC) at KU Leuven, Belgium]

In light of ongoing efforts to revive full-fledged peace negotiations between Russia and Ukraine, the question of sanctions inevitably arises. Although sanctions will likely be considered within the broader framework of peace talks, it remains doubtful whether they will be fully lifted – particularly those imposed by the European Union (EU). The EU’s current position is that restrictive measures should remain in place until a just and lasting peace is achieved, suggesting that a mere ceasefire would not suffice.

In 2022, the EU unequivocally condemned Russia’s aggression and adopted sanctions to pressure it to end its illegal war against Ukraine. These sanctions range from suspending diplomatic relations and imposing travel bans to sectoral embargoes and freezing the Russian Central Bank’s reserves and assets. However, once hostilities come to an end, wouldn’t that mean that the continued maintenance of these sanctions could no longer be justified by the original rationale of ending the war of aggression? 

This post argues that there are viable options to justify EU sanctions following a potential peace settlement between Russia and Ukraine. It begins by examining the international legal nature of EU sanctions and how they are perceived by the Court of Justice of the European Union (CJEU). Building on this foundation, it proposes the framework of third-party countermeasures as the most suitable basis for assessing their legality under three scenarios: countermeasures in response to an ongoing act of aggression, countermeasures against a breach of the obligation to provide reparation, and countermeasures against other breaches of obligations erga omnes. 

The Nature of EU Sanctions

Under EU law, the power to impose sanctions (restrictive measures) derives from Article 29 of the Treaty on European Union (TEU) and Article 215 of the Treaty on the Functioning of the European Union (TFEU). These provisions grant the Union internal competence to adopt sanctions in the framework of the Common Foreign and Security Policy. However, they do not specify the international legal basis for such measures.

The European Union is obliged, when adopting an act, to respect international law in its entirety, including customary international law. This obligation, affirmed by the CJEU in Air Transport Association of America and Others (§ 101), stems from Article 3(5) TEU, which commits the Union to contribute to the strict observance and development of international law. In line with this, the Council of the EU’s Sanctions Guidelines specify that restrictive measures must always comply with international law (§ 9). Accordingly, establishing a sound international legal justification is essential to ensure that the EU acts consistently with its own commitments.

EU restrictive measures against Russia are autonomous, or unilateral, meaning that they have not been authorized by the UN Security Council under Article 41 of the UN Charter. The UN General Assembly has repeatedly condemned the use of ‘unilateral coercive economic measures’ that are not authorized by the relevant UN organs and that are inconsistent with international law. Similarly, in their recent declaration (§ 14), BRICS leaders condemned the use of unilateral coercive measures and economic sanctions, reaffirming the UN Security Council’s exclusive authority to impose sanctions. Russia, in particular, has characterized the EU’s sanctions as “illegitimate unilateral coercive measures”.

This leads to the question of whether the EU’s unilateral sanctions are lawful under international law.

EU Sanctions in the CJEU’s Case Law

The Union’s institutions have long avoided classifying EU restrictive measures in international legal terms such as «countermeasures». In Venezuela v Council, the CJEU had an opportunity to clarify the nature of EU autonomous sanctions but chose not to.

The case concerned sanctions against Venezuela imposed ‘in view of the risk of further violence, excessive use of force, and human rights abuses’ (recital 8). The measures included travel bans, asset freezes, and an arms embargo. Venezuela advanced an international legal argument before the Court, contending that the sanctions constituted unlawful countermeasures and thus infringed customary international law (§ 83). The Court disagreed, holding that the sanctions in casu were not countermeasures at all because they were preventive, not reactive, and did not suspend any EU obligations owed to Venezuela (§ 91-92).

Importantly, the Court dismissed the countermeasure argument on factual grounds rather than in principle, leaving open the possibility that EU sanctions could qualify as such in other circumstances. While the Court referred to Article 3(5) TEU (§ 87, 113), it ultimately justified the measures by invoking EU law provisions only (§ 95, 110, 113), clarifying their internal legality but not their status under international law.

In RT France v Council, the Court observed that the purpose of the sanctions imposed on a Russian state-controlled broadcaster was to counter a ‘violation of obligations imposed erga omnes by international law in order to counter, using all the measures at its disposal that did not involve the use of force, the military aggression against Ukraine’ (§ 86). This stated objective of the sanctions aligns with the rationale underlying third-party countermeasures, a concept often used by scholars when analyzing the EU’s autonomous sanctions. However, the Court refrained from employing the term countermeasures – perhaps because the applicant did not raise the argument concerning unlawful countermeasures.

However, if Russia, like Venezuela, were to challenge the EU sanctions and argue that they constitute unlawful countermeasures, it would be far more difficult for the Court to dismiss the claim. The sanctions clearly respond to a breach of an erga omnes norm (the prohibition of aggression) and involve the suspension of certain obligations owed to Russia. This would place the Court in a position where it may ultimately have to rule on the international legal status of the EU’s sanctions.

EU Sanctions as Third-Party Countermeasures

Even though the international legal status of the EU’s autonomous sanctions remains unresolved, a potential Russia–Ukraine peace settlement would inevitably have significant implications for the EU sanctions regime. The cessation of hostilities could make the existing legal and political justification for these measures, namely, to compel Russia to end its war of aggression, less straightforward, thereby necessitating a careful reassessment of the implications of maintaining them.

For the purposes of assessing the implications of a future peace agreement between Russia and Ukraine for the EU sanctions regime, this post will treat the EU’s restrictive measures as third-party countermeasures. 

Traditionally, the right to take countermeasures belonged only to an injured state, allowing it to suspend certain obligations towards the responsible state to induce compliance. However, in recent decades, there has been a growing practice of states and international organizations not directly injured by an internationally wrongful act resorting to countermeasures in response to violations of erga omnes (partes) obligations. Such measures are known as third-party countermeasures.

Third-party countermeasures have become increasingly common in state practice, and their legality is gaining growing recognition in international scholarship. They therefore provide the most solid and credible legal basis for the EU’s sanctions. Moreover, the CJEU’s reasoning in RT France v Council reflects the same underlying rationale, portraying the EU’s restrictive measures against Russia as responses to erga omnes breaches.

Countermeasures and Continuing Aggression

Any future peace arrangement between Russia and Ukraine will likely take the form of a ceasefire, freezing hostilities along current frontlines. Russia would still control the occupied Ukrainian territories, meaning the violation of the prohibition on the use of force would continue. This interpretation aligns with the UN General Assembly’s Definition of aggression resolution (Art. 3) and the International Law Commission’s commentaries on Article 14(2) of the Articles on Responsibility of States for Internationally Wrongful Acts (ARSIWA), which describes unlawful occupation as a continuing wrongful act.

As long as the wrongful act persists, countermeasures remain justified. The rationale for maintaining EU sanctions after a ceasefire would therefore remain unchanged: to compel Russia to end its ongoing aggression. This view is consistent with the EU’s official position that lifting sanctions requires the full withdrawal of Russian forces from Ukrainian territory.

Countermeasures and Reparations

A less likely scenario (perhaps following a regime change) would involve Russia withdrawing its troops from Ukraine but refusing to provide reparations. Under international law, countermeasures must end once the responsible state fulfils its obligations arising from the wrongful act (Art. 53 ARSIWA). One of these obligations is the duty to provide full reparation (Art. 31 ARSIWA). The obligation to provide reparation constitutes a separate secondary obligation arising from the breach of a primary obligation. This means that failure to provide reparation amounts to an independent breach of international law, which entails distinct international responsibility.

In 2022, the UN General Assembly affirmed that Russia must bear the legal consequences of its wrongful acts, including the obligation to make reparations. Likewise, the G7 declared that Russia’s sovereign assets would remain frozen until it ends its aggression and compensates Ukraine, implying that some countermeasures will remain until reparations are provided.

It remains to be determined whether the violation of a secondary obligation to provide reparations, stemming from the breach of a primary erga omnes obligation, such as the prohibition of aggression, equally amounts to an erga omnes breach. Oona Hathaway argues that it does. Drawing on the Chagos Archipelago Advisory Opinion of the International Court of Justice, she highlights the Court’s recognition of both the UK’s obligation to end its unlawful administration of the Archipelago and the broader duty of all States to assist in its complete decolonization, including resettlement on the Archipelago of Mauritian nationals. This, she suggests, demonstrates that erga omnes obligations are not exhausted by cessation of a wrongful act alone. By analogy, Hathaway contends that Russia’s aggression triggers a continuing collective interest not only in ending the war, but also in ensuring reparations to Ukraine as part of restoring international legality. (pp. 1032-1033).

Countermeasures and other erga omnes breaches

There is a view that argues that a peace deal requiring Ukraine to recognize Russia’s sovereignty over certain territories might not necessarily be considered void under Articles 52 or 53 of the Vienna Convention on the Law of Treaties. Without prejudice to the present author’s opinion, if such an agreement were concluded, the EU might, for political reasons, refrain from questioning its legality to avoid destabilizing a fragile peace. In that case, the EU could maintain its sanctions on alternative legal grounds, shifting its justification from aggression to continuing breaches of other erga omnes obligations.

For example, the prohibition of crimes against humanity. The Independent International Commission of Inquiry on Ukraine has documented enforced disappearances and torture by Russian authorities in occupied territories (p. 1). As long as such violations persist, sanctions would remain legally defensible.

Conclusion

This post has outlined three potential scenarios for maintaining sanctions under different peace arrangements. In each, EU sanctions can be understood as third-party countermeasures grounded in a collective response to erga omnes breaches. This framework remains the most stable and persuasive option for justifying their legality within the international legal order.

Whether in reaction to ongoing aggression, failure to provide reparations, or continued human rights violations, the Union’s restrictive measures reflect its broader commitment, affirmed in RT France, to uphold the most fundamental norms of international law.

Author’s note: This piece was written before Donald Trump’s peace proposals were published and does not take them into account.