Post Achmea and Komstroy, arbitration provisions in bilateral investment treaties have come into doubt with respect to intra-EU disputes between investors and EU member states.  Most recently, the Contracting Parties to the Energy Charter Treaty (ECT) on June 24, 2022, announced their agreement in principle on the modernisation of the ECT.[1]  Part of the agreement “confirm[s] that an investor from a Contracting Party that is part of a regional economic integration organisation (REIO), like the EU, cannot bring an Investor-state dispute settlement (ISDS) claim against another Contracting Party member of the same REIO.”  The Parties addressed that aspect in order to “finally bring an end to the intra-EU applications under the ECT that are contrary to the EU law and recent judgments by the Court of Justice of the EU.”  This post summarizes the background, recent decisions post-Achmea and Komstroy, and the resort to enforcement outside of the EU, particularly the actions pending in the United States.

The Achmea and Komstroy Decisions

In Slovak Republic v. Achmea B.V, the Court of Justice of the European Union (CJEU) held that EU member states could not agree to a treaty that permitted an investor to “bring proceedings against the latter Member State before an arbitral tribunal whose jurisdiction that Member State has undertaken to accept.”[2]  Twenty-three EU member states subsequently entered into an agreement to implement Achmea by terminating bilateral investment treaties among themselves.[3]  In 2021, the Grand Chamber of the CJEU further extended Achmea to multilateral treaties such as, in that case, the Energy Charter Treaty.[4]  This lead to the June 24 announcement that the EU member states reached an agreement in principal to remove the ability of EU-based investors to commence arbitration proceedings against EU member states under the Energy Charter Treaty.[5]

On September 2, 2021, the Grand Chamber of the CJEU addressed the arbitration provisions of the multilateral ECT in Moldova v. Komstroy LLC.[6]  The CJEU found that the arbitration provision in the ECT “must be interpreted as not being applicable to disputes between a Member State and an investor of another Member State.”[7]  The CJEU’s decision was based on Achmea, as the court found that the arbitration provision in the Energy Charter Treaty was inapplicable “[i]n precisely the same way as the arbitral tribunal at issue . . . in Achmea” because an arbitral panel constituted under that provision “does not constitute a component of the judicial system of a Member State.”[8]

Developments Regarding Arbitration Awards Post Achmea and Komstroy

Despite the foregoing, EU member states have largely been unsuccessful in getting arbitral panels to annul prior awards or otherwise decline jurisdiction.  In one recent decision, an arbitral panel of the International Centre for Settlement of Investment Disputes (ICSID) rejected an attempt by Spain, based on Achmea and subsequent decisions, to annul a 2019 arbitration award issued by the panel under the Energy Charter Treaty.[9]  The panel effectively held that the CJEU could not unilaterally amend the plain text of a multilateral treaty and that, in any event, ICSID “has no national juridical seat” and thus is not bound by EU law.[10]  But at least one non-ICSID arbitral tribunal has sustained jurisdictional objections and dismissed an arbitration where no award had yet been issued and where the seat of arbitration was in an EU member state (Sweden), holding that Achmea’s reasoning “is fully applicable to investor-State disputes under the” treaty at-issue.[11]  The panel rejected the conclusions of other arbitral panels to the contrary, including by finding ICSID decisions “inapposite” because, unlike in ICSID arbitrations that do not have a jurisdictional seat, the arbitration here had its “seat in an EU Member State,” Sweden.[12]  The panel ultimately concluded that “Spain is precluded under [the] TFEU to offer to submit to arbitration a dispute with investors from another EU Member State, such as the Claimants.”[13]  Thus, “the Tribunal does not have jurisdiction to hear the claims brought by the Claimants.”[14]


Claimants have turned to the U.S. courts as they seek to enforce arbitral awards against EU sovereigns outside of Europe.  Spain in particular has sought to dismiss several enforcement proceedings based on Achmea and its progeny.[15]  The arbitration claimants have disputed Spain’s arguments, and the motions remain pending.  For example, in Cube Infrastructure, Spain has raised four arguments supporting its motion to dismiss – three of them based in whole or part on Achmea.  One argument focuses squarely on the validity of an agreement to arbitrate among intra-EU parties post Achmea and Komstroy.

Under the Foreign Sovereign Immunities Act, U.S. courts do not have subject matter jurisdiction unless certain exceptions apply, including the sovereign’s agreement to arbitrate or its waiver of sovereign immunity.[16]  Spain argued that the FSIA exceptions could not apply because, among other things, in light of Achmea and Komstroy, Spain never made a valid agreement to arbitrate.[17]  Next, Spain invoked Achmea in partial support of its argument that enforcing the arbitration award at issue would violate the foreign sovereign compulsion doctrine because forcing it to comply with the arbitration award would require Spain to violate EU law as set forth in Achmea.[18]  Spain also argued that the arbitration award is not entitled to full faith and credit as if it were a final judgment of a U.S. state court because, among other reasons, the arbitral panel lacked jurisdiction to hear the dispute because there was no valid agreement to arbitrate presumably based in part upon Achmea and Komstroy.[19]

There remains significant uncertainty about the viability of intra-EU arbitrations under bilateral investment treaties.  Although ICSID panels in particular may seem poised to continue to continue to exercise jurisdiction over these disputes, claimants may find themselves unable to enforce ICSID awards and other awards in the courts of EU member states.  The U.S. remains a possible option for now, but pending motions in the U.S. could change that situation.  Potential intra-EU litigants in particular should keep a close watch on these developments.

[1] The announcement is available at

[2] CJEU Case No. C-284/16 ¶ 62, available at


[4] Moldova v. Komstroy LLC, CJEU Case No. C-741/19,


[6] CJEU Case No. C-741/19, available at

[7] Id. ¶ 66.

[8] Id. ¶ 52.

[9] RREEF Infrastructure (G.P.) Limited and RREEF Pan-European Infrastructure Two Lux S.A.R.L. v. Kingdom of Spain, ICSID Case No. ARB/13/30, available at

[10] Id. ¶¶ 97-98.

[11] Green Solar Partners K/S SCE Solar Don Denito APS v. Kingdom of Spain, SCC Arbitration V (2016/135), ¶¶ 427, 431, available at[0]=en.

[12] Id. ¶ 439.

[13] Id. ¶ 456.

[14] Id. ¶ 479.

[15] See, e.g., Cube Infastructure Fund SICAV v. Spain, 20-cv-1708 (D.D.C.); Nexterra Energy Global Holdings B.V. v. Spain, 19-cv-1618 (D.D.C.).

[16] See id. at 16 (citing 28 U.S.C. § 1605(a)(1), (6)).

[17] Id. at 17-24. Spain also argued that agreeing to arbitrate under the ICSID Convention was not an express or implied waiver of its sovereign immunity. Id. at 20-24.

[18] Id. at 24-25. Spain added a second prong to this argument, positing that forcing it to pay the award “would require Spain to make unlawful payments in violation of EU [state] aid law” as the payment was not authorized by the European Commission.

[19] Id. at 25-26.