In Achmea, the Court of Justice of the European Union (CJEU) was asked to assess the compatibility of the dispute resolution clause contained in the Netherlands-Slovak Republic BIT with EU law. In March 2018, the CJEU held that the clause was incompatible based on the threat posed to the constitutional structure and autonomy of the legal system of the EU. Moreover, it was deemed incompatible with the principles of mutual trust and sincere cooperation. Based on this judgment, the German Federal Court of Justice set aside the final arbitral award in Achmea.
Afterwards, in a series of declarations published on the European Commission’s website in January 2019, all 28 Member States of the European Union agreed to terminate the BITs concluded between them by 6 December 2019, in order to conform with the Achmea judgment of the CJEU.
A majority of the Members States also agreed to a variety of commitments, including to prevent intra-EU investor-State arbitrations from even being filed under the ECT. Member States committed:
• that no new intra-EU investment arbitrations should be initiated;
• to take steps under national laws to withdraw any pending investment arbitration cases brought by Member State-controlled entities against another Member State;
• to prevent intra-EU investor-State arbitrations from being filed under the ECT. Future developments will shed greater light on how this commitment to prevent investor-State arbitrations being filed under the ECT will actually be implemented. While this commitment was signed by most EU States, Finland, Luxembourg, Malta, Slovenia, Sweden and Hungary refused to sign this commitment regarding the ECT by noting the findings of the latest investment arbitrations tribunals that Achmea does not apply, and signed separate declarations;
• that the sunset or grandfathering provisions that provide that investment protections continue for a specific period following termination of a BIT do not produce effects; and
• to request the courts of any country deciding proceedings relating to an intra-EU arbitration award to either set the award aside or refuse to enforce it, because of a lack of valid consent to the dispute being resolved by arbitration.
Despite Achmea and the declarations, however, most arbitral tribunals actually involved in intra-EU arbitrations have to date either adopted a narrow interpretation of the Achmea judgment or sidestepped the issue entirely, as shown by the following decisions:
• In Antaris v Czech Republic, the tribunal refused to apply Achmea on the basis that the Czech Republic waived any objection on jurisdiction in its counter-memorial stating “the Czech Republic does not pursue the jurisdictional objection articulated by the Commission before the Tribunal.”
• In Masdar v Spain, the tribunal based its jurisdiction on Article 26 of the ECT, despite objections arguing the intra-EU character of the dispute, and denied Spain’s request to reopen the arbitration following Achmea, indicating that the “Achmea judgment is simply silent on the subject of the ECT.”
• In Antin v Spain, the tribunal refused to reopen Spain’s argument on jurisdiction based on Achmea and concluded that nothing in the ECT suggests that a “development in European law could be employed to undermine the prior consents to submit to arbitration under the ECT given by each of the EU Member States and the EU itself”.
• In Vattenfall v Germany, the arbitral tribunal rejected Achmea by holding that EU law is not part of general international law and that it should not override the ECT. It held that EU law “is not general law applicable as such to the interpretation and application of the arbitration clause in another treaty such as the ECT”. One may expect Vattenfall to be relied upon by future arbitral tribunals, as it squarely addresses Achmea’s impact on intra-EU ECT arbitration in a reasoned manner.
• The UP and CD Holding v Hungary arbitral tribunal also rejected Achmea-based objections, with the tribunal holding that “the Achmea decision contains no reference to the ICSID Convention or ICSID arbitration [and] cannot be understood or interpreted as creating or supporting an argument that, by its accession to the EU, Hungary is no longer bound by the ICSID Convention”.
• In Greentech v Spain, the tribunal echoed Masdar’s reasoning on jurisdiction and considered that EU law was not relevant for its jurisdictional analysis and that Achmea could not be transposed to investor-State arbitration under the ECT;
• In RREEF Infrastructure (G.P) Limited and another  the tribunal’s jurisdiction was also affirmed, despite Spain’s intra-EU objections.
• In Novenergia v Spain, Spain has asked the Svea Court of Appeal in proceedings to set aside the Novernergia award and to seek a preliminary ruling from the CJEU on the compatibility of the ECT with EU law. On 17 May 2018, the Svea Court granted Spain’s request for suspension and ordered that the arbitral award not be enforced until further notice.
• In PL Holdings v Poland, Poland challenged the awards by invoking Achmea, but the Svea Court of Appeal stated that the award in question involved questions of breach of contract and liability for compensation which the parties were able to settle, which could be determined by arbitrators. In addition, it found that Poland’s jurisdictional objections were untimely.
In light of the above, arbitral tribunals to date do certainly seem to hold that Achmea does not deprive them of jurisdiction or provide a basis to reopen proceedings or to restrict ECT arbitrations.
The Achmea judgment, the recent European declarations on future policies, and the lack of clarity regarding the legal consequences of these decisions, do create considerable uncertainty, however, with the main risk for claimants being enforcement issues and setting aside proceedings (if the proceedings are brought on the basis of the UNCITRAL Rules). It is moreover not implausible that a future arbitrator will attempt to reconcile Achmea with international law, as there is no binding precedent in arbitration.
If intra-EU ECT arbitrations are not initiated yet or pending, it is uncertain whether the cases will be affected by the 2019 Member States declarations and what steps, if any, to prevent intra-EU investor-State arbitrations being filed under the ECT will be taken.
Clearly, if intra-EU ECT arbitrations are initiated under either the UNCITRAL Rules or pursuant to the ICSID Convention, the enforcement of awards in the EU is endangered. Recently, for instance, the District Court of Nacka in Sweden refused enforcement of the ICSID award obtained by the Miculas against Romania. The court held that absent any decision by the Court of Justice of the EU to the contrary, the European Commission decision that payments made pursuant to the award would constitute illegal State aid must be respected.
While investors may continue to seek enforcement of awards outside of the EU, as is the case for the Masdar, Novenergia and Antin awards which are the subject of enforcement proceedings in the District of Columbia, and there is a chance that U.S. Courts will not consider EU law to be relevant, it remains to be seen how U.S. Courts will actually decide.
 Slovak Republic v Achmea B.V., Case C-284/16, 2018.
 Declaration of the Representatives of the Governments of the Member States of 15 January 2019 on the Legal Consequences of the Judgment of the Court of Justice in Achmea and on Investment Protection in the European Union.
 The remaining states held that Achmea judgement is silent on the question of intra-EU arbitration under the ECT (Finland, Luxembourg, Malta, Slovenia, Sweden, Hungary).
 Second declaration signed 16 January 2019 by Finland, Luxembourg, Malta, Slovenia and Sweden; Third declaration signed 16 January 2019 by Hungary.
 Paschalidis Paschalis, Sadowski Wojciech, EU countries to cancel BITs post-Achmea, 17 January 2019.
 Antaris v Czech Republic, PCA Case No. 2014-01 at 73.
 Masdar Solar & Wind Cooperatief U.A. v Kingdom of Spain, ICSID Case No. ARB/14/1 at 682.
 Antin Infrastructure Services Luxembourg SARL and Antin Energia Termosolar BV v Kingdom of Spain, ICSID Case No. ARB/13/31 at 224.
 Vattenfall AB and others v Federal Republic of Germany, ICSID Case No. ARB/12/12 at 133.
 UP an and C.D. v Hungary, ICSID Case No. ARB/13/35 at 258.
 Greentech Energy Systems A/S, Foresight Luxemborg Solar 1 SARL, Foresight Luxembourg Solar 2 SARL, GWM Renewable Energy I SPA and GWM Renewable Energy II SPA v Kingdom of Spain, SCC Arbitration V 2015/150 at 218-221.
 RREEF Infrastructure (G.P.) Limited and RREEF Pan-European Infrastructure Two Lux SARL, ICSID Case No. ARB/13/30 at 88-90.
 Novenergia II – Energy & Environment (SCA) (Grand Duchy of Luxembourg), SICAR v The Kingdom of Spain, SCC Case No. 2015/063.
 Novenergia II – Energy& Environment (SCA) v The Kingdom of Spain, Respondent the Kingdom of Spain’s Memorandum of Law in Support of Motion to Dismiss and to Deny Petition to Confirm Foreign Arbitral Award, No. 1:18-cv-1148, 16 October 2018 at VI.
 PL Holdings v Poland, SCC Case No. 2014-163; Svea Court of Appeal, 22 February 2019 (T8538-17) at 5.2.3.
 Slovak Republic v Achmea B.V., Case C-284/16, 2018.
 Dahlquist Joel, Swedish Court Declines to Enforce an ICSID Award, but on EU Law Grounds Without Addressing Question of Post-Achmea Validity of Intra-EU BITs, Investment Arbitration Reporter 5 February 2019; Nikos Lavrakos, A new Micula-type case on the horizon? 25 January 2018 Pratical Law arbitration Blog; Paschalidis Paschalis, Sadowski Wojciech, EU countries to cancel BITs post-Achmea, 17 January 2019, Wojciech Sadowski predicts a “pushback” from international investors especially with respect to ECT and ICSID cases.
 Micula v Romania, Case No. 2550-17. Masdar & Wind Cooperatif UA v Kingdom of Spain: Petition to Enforce Arbitral Award at the U.S. District Court of Columbia 28 September 2018; Infrastructure Services Luxembourg SARL (formerly Antin Insfrastructure) and Energia Termosolar BV (formerly Antin Energia Termosolar BV) v Kingdom of Spain: Petition to Enforce Arbitral Award at the U.S. District Court of Columbia 27 July 2018; Novenergia II -Energy & Environment (SCA) v Kingdom of Spain: Petition to Enforce Arbitral Award at the U.S. District Court of Columbia 16 October 2018.