The DC Circuit Court of Appeals’ August 2024 decision in NextEra Energy v. Spain¹ is reshaping the enforcement landscape for arbitral awards in US courts, particularly for awards arising from intra-EU disputes under the Energy Charter Treaty (“ECT”).  As discussed in a prior client alert, the DC Circuit's decision clarified that US district courts have jurisdiction under the Foreign Sovereign Immunities Act’s (“FSIA”) arbitration exception to confirm arbitral awards issued in intra-EU disputes under the ECT – a significant development given the Court of Justice of the European Union’s (“CJEU”) decisions in Slovak Republic v. Achmea and Moldova v. Komstroy, making it more difficult in EU courts for investors to enforce intra-EU arbitration awards against EU Member States.      

Although NextEra opened US courts to the enforcement of intra‑EU arbitral awards, the arbitration enforcement landscape in the United States remains in flux.  Spain has sought US Supreme Court review of the DC Circuit’s decision.  In the meantime, district courts have proceeded to enforce arbitral awards against Spain on the merits, and Spain recently filed a notice of appeal from one such enforcement decision.  As these proceedings unfold, both investors and sovereign parties to arbitration will face an evolving US legal landscape.  This client alert highlights the key developments and practical implications for the enforcement of foreign arbitral awards in US courts, roughly a year-and-a-half after NextEra.

A. The DC Circuit's Decision

The DC Circuit’s decision in NextEra opened wider US courtroom doors to parties seeking to enforce investor-state awards against foreign states under the FSIA’s arbitration exception to sovereign immunity.  Before the DC Circuit’s decision, enforcement of intra-EU ECT awards in the United States was complicated by conflicting interpretations among federal district courts in DC regarding how the CJEU’s decisions in Slovak Republic v. Achmea² and Moldova v. Komstroy³ impacted jurisdiction under the FSIA’s arbitration exception.  In Achmea, the CJEU held that investor‑State arbitration clauses in intra‑EU BITs were incompatible with EU law. Komstroy expressly extended that reasoning to the ECT, holding that intra‑EU investor‑State arbitration under the ECT likewise violates EU law. Relying on this line of authority, Spain and other EU Member States have argued that no valid agreement to arbitrate existed with EU investors under the ECT and thus the FSIA’s arbitration exception to sovereign immunity did not apply.  

The DC Circuit’s decision consolidated appeals from three cases involving ECT awards against Spain.⁴ The central issues were whether the FSIA’s arbitration exception applies and whether US courts are a proper forum for enforcement of intra-EU arbitration awards. Spain also sought anti-suit injunctions in European courts, prompting US petitioners to counter the potential effect of any such injunctions by petitioning DC courts for anti-anti-suit injunctions that would protect US jurisdiction from interference by European courts.

First, the DC Circuit held that under the FSIA, jurisdiction over a foreign state turns on the existence of an arbitration agreement, not on the scope of that agreement.  Thus, the DC Circuit concluded that because Article 26 of the ECT provides a standing offer to arbitrate, petitioners were able to establish the existence of arbitration agreements sufficient to satisfy the arbitration exception to sovereign immunity. Furthermore, the DC Circuit concluded that Spain’s argument that EU law, after Achmea, forbids arbitration with EU investors concerned the scope of the arbitration agreement (more specifically, whether any such agreement applies within the EU), not its existence, and thus did not prevent US courts from exercising jurisdiction in cases seeking to enforce intra-EU arbitration awards against EU Member States.

Second, citing circuit precedent,⁵ the DC Circuit reaffirmed that forum non conveniens is unavailable in award-enforcement cases. Given that US courts can attach a sovereign’s assets only to the extent those assets are located in the United States, the Court of Appeals concluded that the doctrine does not apply.

Finally, the DC Circuit reversed the district court’s issuance of anti-anti-suit injunctions to prevent Spain from seeking in foreign courts to enjoin the US enforcement proceedings. The Court of Appeals emphasized that such orders against foreign sovereigns raise serious comity concerns and rarely are justified.  We discussed in our prior client alert that the DC Circuit’s ruling on anti-anti-suit injunctions potentially blunts the impact of its jurisdictional ruling, as it leaves open the possibility that EU sovereign award debtors will seek and obtain anti-suit injunctions in European courts to frustrate the exercise of jurisdiction by US courts over intra-EU award enforcement actions against EU states.  Anti-anti-suit injunction issues have not reappeared in any cases since the DC Circuit decided NextEra. 

B. NextEra in Application

The practical impact of the DC Circuit’s jurisdictional decision thus far has been to pave the way for enforcement of intra-EU arbitration awards in US courts – although there are still important issues to be resolved in US courts.

In NextEra itself, and the related 9Ren case – which was subject of the same appeal to the DC Circuit – the district court had little trouble deciding to enforce the arbitration awards against Spain following the DC Circuit’s decision that the district court had jurisdiction.  The awards in both NextEra and 9Ren were issued under the auspices of the ICSID Convention, which provides that ICSID awards that impose pecuniary obligations are treated as final judgments of US state courts – i.e., they are given “full faith and credit” as valid judgments under US law.⁶ Spain argued that these intra-EU awards were not entitled to such treatment because the ICSID tribunal did not have jurisdiction to issue the award under EU law.  The district court rejected this argument on the ground that the ICSID Convention bars US courts from examining the arbitral tribunals’ decisions on jurisdiction and that the issue had been fully and fairly litigated before the tribunals.⁷

Spain also argued that enforcing the awards would force it to violate EU law and thus should be refused on the basis of the foreign sovereign compulsion doctrine and principles of international comity. The district court rejected that argument, concluding that principles of international comity favored confirming and enforcing awards issued by foreign tribunals, especially under the ICSID Convention, which reflects the will of states-parties.

The district court’s rulings in these cases indicate that intra-EU arbitration awards issued under the ICSID Convention will often be easily confirmed following the DC Circuit’s decision on jurisdiction in NextEra.  This is pending the Supreme Court’s decision on whether it will review the DC Circuit’s decision, discussed below. On March 5, 2026, Spain also filed a notice of appeal from a related district court decision enforcing a separate ICSID award, which would bring before the DC Circuit Spain’s challenges to enforcement on the merits.⁸

Intra-EU arbitration awards that are not rendered under the ICSID Convention, and instead are governed by the New York Convention, appear to be a different story.  Unlike ICSID awards, New York Convention awards do not receive full faith and credit akin to US state-court judgments and thus remain subject to Convention defenses against recognition and enforcement, including the provision allowing (but not requiring) courts to deny confirmation of an award that is lawfully set aside at the seat of the arbitration.⁹ Thus, in the recent decision of Mercuria v. Poland,¹⁰ the US District Court for the District of Columbia refused confirmation of an ECT award issued under the Stockholm Chamber of Commerce Rules in an arbitration seated in Sweden, where a Swedish court had set aside the award under Achmea (i.e., that such arbitration is contrary to EU law and thus unenforceable in the EU).  This was so even though the district court found jurisdiction under the FSIA’s arbitration exception, citing NextEra. 

In short, for ECT awards governed by the New York Convention, NextEra may by analogy help to establish jurisdiction, but it will not guarantee confirmation and enforcement.  Unlike ICSID awards – where confirmation is mandatory once the award receives full faith and credit under US law – US courts retain discretion to refuse confirmation of non-ICSID awards based on the grounds set forth in the New York Convention.  This highlights the importance of forum selection for investors seeking to arbitrate disputes under the ECT.  In particular, investors might increasingly seek arbitration under the ICSID Convention because annulment occurs exclusively before an ICSID annulment committee – insulated from EU law and national courts – reducing the risk that an award will be set aside on Achmea/Komstroy grounds.  While an annulled ICSID award is likewise unenforceable, the ICSID framework significantly narrows the grounds for annulment.      

C. Supreme Court Review and What to Expect

The DC Circuit’s NextEra decision and subsequent developments in the district courts suggest that US courts are a good forum for seeking confirmation and enforcement of intra-EU awards, but the DC Circuit may not have the last word.  In May 2025, Spain filed a petition for certiorari seeking the Supreme Court’s review of the DC Circuit's decision.¹¹ In October 2025, the Supreme Court requested the Solicitor General’s views on whether to grant certiorari.  While the US Government previously supported Spain before the DC Circuit, the Solicitor General’s current position remains unknown.  If the Supreme Court grants review, its decision on the merits of these issues could provide the definitive word on the viability of efforts to enforce intra-EU arbitration awards in US courts.