Isn’t it Ironic? The Consistent Case Law in Response to Intra-EU Jurisdictional Objections in Investor-State Disputes
Since the Court of Justice of the European Union (CJEU) issued the Achmea judgment, it became apparent that the days of investor-State arbitration were numbered within the European Union (EU). The ruling was also a catalyst for stronger advocacy of the EU Commission at the international stage for the abandonment of the ad hoc system of investor-State arbitration, and the establishment of a standing Multilateral Investment Court (MIC).
One of the main criticisms of the existing investor-State dispute settlement (ISDS) system levied by the EU is the prevalence of “unjustifiably inconsistent interpretations of investment treaty provisions”, even in instances where the tribunals are interpreting the same underlying treaty. Therefore, the EU and its Member States took the position that only a standing investment court with full-time judges could ensure consistency and predictability of outcomes in ISDS, since the existing ad hoc system could not be expected to follow rulings issued in previous cases. In relation to EU law, the CJEU reaffirmed this concern in the Achmea ruling, stating that arbitral procedures could not ensure the uniform application of EU law. Therefore, any reform of the existing ISDS system is deemed insufficient and only a systematic change can improve the consistency and correctness of ISDS awards.
The Achmea ruling also quickly found its way into ongoing investment arbitrations between EU investors and the host Member States. Although jurisdictional challenges on the basis of incompatibility of intra-EU ISDS with EU law were already commonly raised, Achmea was a fresh and explicit affirmation of the long-held view within the EU that intra-EU ISDS was incompatible with EU law. These challenges were often supported by amicus curiae submissions by the EU Commission, echoing the primacy of EU law over the contested treaty provisions.
These challenges provided an opportunity for ISDS tribunals to showcase a remarkable convergence of interpretations and positions in cases governed by different treaties. Tribunals in both BIT (bilateral investment treaties) and ECT (Energy Charter Treaty) cases recognized similar weaknesses of the intra-EU challenges under international law and upheld their jurisdiction in all cases. In addition to hindering the desired effects of the Achmea judgment at the international level, the uniform rejection of intra-EU jurisdiction challenges stands in stark contrast to the image of ISDS tribunals portrayed by the EU, as a system unable to render consistent and coherent decisions on related matters.
Before delving into this analysis, the article provides a summary of the Achmea judgment, and a timeline of the steps taken by the EU and its Member States towards its implementation. Then the article analyzes the most prominent decisions addressing the intra-EU jurisdictional challenges, outlining the reasoning applied to the consistent rejection of such challenges to date. The article concludes that ironically, the persistent interference with ongoing arbitrations has yielded a consistent body of case law rejecting the primacy of EU law in treaty-based ISDS.
The floodgates open: Achmea and its aftermath within the EU
The Achmea case originated from arbitral proceedings brought by Achmea B.V. (formerly known as Eureko B.V.) against Slovakia for alleged breaches of the Slovakia-Netherlands BIT. The tribunal in the Frankfurt-seated arbitration ruled in favor of Achmea in 2012, ordering Slovakia to pay EUR 22.1 million in damages. Slovakia initiated proceedings before German higher courts to set aside the award. Ultimately, the German Federal Court of Justice referred questions on the compatibility of the BIT dispute resolution clause with EU law to the CJEU for a preliminary ruling. The preliminary position of the German Federal Court was that the ISDS clause in the underlying treaty was not contrary to EU law. This was also supported in the Opinion of the Advocate General Wathelet, who stated that the arbitral tribunal constituted under a BIT was a ‘court or tribunal of a Member State’ which could request the CJEU for a preliminary ruling. He also explicitly stated that the substantive and ISDS provisions of the ECT are also likely to be compatible with EU law.
The CJEU diverged from the position of the German court and the Attorney General, and found that the dispute resolution clause in the Netherlands-Slovakia BIT was incompatible with the exclusive jurisdiction of the CJEU to give preliminary rulings concerning the interpretation of EU treaties, as provided in the Treaty of the Functioning of the EU (TFEU). The Court reasoned that, by agreeing to submit the disputes between investors and the State to bodies outside of the EU judiciary, the Member States were authorizing arbitral tribunals to interpret EU law, thus removing the remedies under EU law from its judicial system. Although the CJEU denounced ISDS clauses “such as the one in Article 8 of the Netherlands-Slovakia BIT” in no uncertain terms, the CJEU did not extend its reasoning beyond the four corners of the underlying treaty. However, the EU Commission saw just enough material in the Achmea ruling to reinforce its long-standing crusade against intra-EU ISDS with jurisprudence from the highest court of the EU.
Immediately after the ruling, the EU Commission took decisive steps towards implementing Achmea both within the EU and internationally, supplementing the CJEU ruling to include all intra EU-BITs and the ECT.
January Declarations on the Effects of Achmea
On 15 January 2019, twenty-two EU Member States signed a Declaration on the effects of the Achmea Judgment, reaffirming the position that Achmea should apply to all intra-EU ISDS arbitrations. In the Declaration, the EU Member States committed to notifying ISDS tribunals and courts about the proper interpretation of Achmea in relation to intra-EU disputes. The Member States further committed to terminating all intra-EU BITs (some 140 BITs in force at the time) and their sunset clauses by the end of 2019. This interpretation of the effects of the Achmea Judgment in the Declaration went beyond the reasoning of the CJEU itself, as it extended beyond intra-EU BITs to multilateral treaties, such as the Energy Charter Treaty (ECT).
Some member States had reservations regarding the effects of Achmea over ECT disputes and thus issued separate declarations on 16 January 2019, undertaking the same overall commitments, but excluding the ECT arbitration from their scope, until the CJEU issues a definitive ruling on this matter. In the separate Declarations, the Member States requested guidance on the investment protection regime under EU law and noted the lack of clarity about the effects of Achmea on ECT arbitrations. Regardless of the diverging positions on the ECT, all Member States explicitly accepted their duty to move forward with the termination of all intra-EU BITs and their sunset clauses, and to notify all arbitral tribunals and courts dealing with pending cases of the effects of Achmea.
The Agreement on the Termination of Intra-EU BITs
After more than two years since Achmea, 23 EU Member States signed the Agreement on the Termination of the Intra-EU BITs (Termination Agreement) on 5 May 2020. The Termination Agreement was the realization of the central commitment provided in the January Declarations – the termination of all applicable intra-EU BITs, including their sunset clauses. In line with the broad interpretation adopted in the January Declarations, the Termination Agreement purported to apply retroactively to all pending arbitrations as an effective bar to the jurisdiction of the sitting ISDS tribunals.
The investors who wished to pursue investment protection remedies under EU law would have to terminate arbitrations and/or enforcement proceedings for awards issued in pending arbitrations, as defined by the Termination Agreement. This would entitle them to pursue amicable settlement (“structured dialogue”) or to resort to national courts, within six months from the fulfillment of the stated requirements. These transitional measures would only be available if an EU court has found in a final judgment that the contested State measure in fact violates EU law. Otherwise, investors whose treaty claims do not fall within the existing investment protection framework under EU law would be left without an effective remedy, even if they received a favorable arbitral award that was not enforced prior to the issuance of the Achmea ruling.
The Termination Agreement does not have any effect on the arbitration awards that were issued and enforced prior to the issuance of the Achmea ruling or those issued in pending arbitrations decided in favor of the State. Although the Termination Agreement provided detailed steps for the transition from intra-EU ISDS to the exclusive application of the EU investment protection mechanisms, it left many questions unanswered and a thorny road ahead for intra-EU investors stripped of their BIT protections.
The adoption of the Termination Agreement and the newly imposed transitional measures for intra-EU disputes did not have any visible effect on the ongoing arbitral proceedings. EU investors continued to pursue their claims in ISDS proceedings, and tribunals upheld their jurisdiction under international law. This was possible mostly due to the uncertainty of the scope of the Achmea ruling and the extent to which the ruling could be applied to ECT arbitrations. The differences in the text of the ruling and the interpretations laid out in the Declarations and the Termination Agreement left enough space for tribunals to uphold jurisdiction under international law. The respondent Member States continued to push forward with the jurisdictional challenges, in line with their commitments expressed in the January Declaration – to insist on the incompatibility of intra-EU arbitration in all its forms as a bar to the jurisdiction of the arbitral tribunals deciding such disputes. Under this intense pressure and scrutiny, ISDS tribunals demonstrated a level of consistency that most critics of the system (including the EU) have long considered unattainable.
The Tribunals Draw a Clear Line: The Steadfast Rejection of Intra-EU Challenges
On the wings of Achmea, Respondent Member States reinforced their intra-EU challenges with the CJEU ruling and the interpretations set forth in the January Declarations. The common thread of these challenges came down to the argument that the Achmea ruling applies to all pending arbitral proceedings under intra-EU BITs and the ECT, and any arbitral tribunal constituted under these provisions lacked jurisdiction.
In essence, these arguments were designed to retroactively establish the incompatibility of intra-EU investment arbitration in the pending ISDS cases. The earliest challenge came as early as May of 2018, two months after the Achmea Judgment and the challenges have continued to date. To support the arguments of the Member States, the EU Commission also frequently requested, and was granted leave to, submit amicus curiae briefs reaffirming the jurisdictional challenges of the Member States, or requesting the termination of the arbitral proceedings. In line with the broad interpretation of Achmea adopted in the January Declarations and the Termination Agreement, the jurisdictional challenges were raised in both intra-EU BIT and ECT arbitrations.
Jurisdictional Challenges in ECT arbitrations
Almost half of all known intra-EU arbitrations were based on the ECT. More than forty of these cases were brought against Spain in light of its reforms to the regulation of the renewable energy sector, seeking compensation in the amount of approximately EUR 7.8 billion. Therefore, it is no surprise that the EU has recognized an interest in avoiding or mitigating the exposure of its Member States to such claims and the enormous damage awards that were pursued by European investors.
The intra-EU jurisdictional challenges in ECT arbitrations mostly revolved around two key points: (i) the ECT dispute resolution provision was never intended to apply to intra-EU disputes, as EU investors filing a claim against a Member State does not qualify as a claim from an “investor of another contracting party” under Article 26 (2)(iii) of the ECT; and (ii) in any case, EU law prevailed over the provisions of the ECT to the extent that they are incompatible. These and related arguments were consistently rejected in clear terms in all cases to date.
In ECT cases involving such challenges, tribunals started their analysis with the meaning of Article 26 of the ECT (the dispute resolution provision of the ECT), focusing on the international framework under which the tribunals were constituted. Namely, the tribunals found that the interpretation of the definition of “area“ under the ECT does not exclude intra-EU arbitration. Although both the EU Member States and the EU are contracting parties to the ECT, the application of the dispute resolution provision for either would depend on who is named as the respondent in the specific case. Tribunals found that there was no carve-out or disconnection clause in the ECT that would exclude intra-EU disputes from the jurisdiction of the arbitral tribunals. As several tribunals noted, the drafters of the ECT made an express carve-out in relation to the application of the Svabland Treaty in Annex 1 of the ECT. In fact, it was noted that an intra-EU disconnection clause was considered and abandoned during the negotiation process. Therefore, the tribunals were satisfied that, if the EU and the other ECT parties had intended to exclude intra-EU disputes from the scope of Article 26, they would and should have done so expressly, and that they would not “lay traps for the unwary with hidden meanings and sweeping implied conclusions.”
Respondent Member States, supported by the EU Commission, also contended that the progressive development of EU law placed investment protection into the exclusive competence of the EU, with the adoption of the Lisbon Treaty, and thus removing it from the external competence of the Member States. Tribunals flatly rejected such assertions, providing detailed analysis of the nature of the system of international treaties governing ISDS arbitration and EU law. In principle, the tribunals held that the Lisbon Treaty and the TFEU did not address the same subject matter as the ECT and they are not a part of the same treaty regime. Although the Member States and the EU Commission argued in favor of the primacy of EU law that would override the international treaties applicable to the jurisdiction of the tribunals, the tribunals found that neither the “EU treaties, the Achmea judgment or any other element of EU law which could be relevant – constitutes such principles of general and transnational application.”
Thus, the tribunals drew a clear line between the EU legal regime and the international treaties and principles of international law governing ECT arbitrations. The tribunals found that the investment protection provisions of the ECT and EU law are not incompatible and that under the principle of treaty parallelism the jurisdiction should be found under the ECT and not the EU legal framework. In any case, the ECT itself provides investors with the option to rely on the more favorable among competing investment protection regimes.
The Member States also argued that the Declarations served as an “agreement to modify” the treaty under the rules of interpretation of the Vienna Convention on the Law of Treaties (VLCT). Tribunals across the board dismissed assertions and held that such political statements do not have any weight in relation to the jurisdiction of the tribunal. Although the title of the Declarations referred to the “Interpretation” of the Achmea ruling, the tribunals found that they did not contain any such analysis, but instead represented a joint stance of the Member States on the ruling. Further, as unilateral statements, the Declarations cannot qualify as “subsequent agreement” or “subsequent practices” of the parties under the VCLT that would modify the effects of the ECT amongst them, as they were not adopted among all ECT Contracting parties. Therefore, the arbitral tribunals faced with intra-EU jurisdictional challenges in ECT arbitrations consistently held that that their jurisdiction was not disturbed whether by the progressive evolution of EU law, nor the Member States’ understanding of the Achmea ruling.
Jurisdictional Challenges in BIT arbitrations
In ISDS disputes raised under intra-EU BITs, the tribunals were also not persuaded by the argument that the Achmea ruling applies to all intra-EU BITs. The specific choice-of-law clause in the Netherlands-Slovakia BIT was a key point of distinction the tribunals made when considering the possible implications of Achmea on their jurisdiction. As other intra-EU BITs did not contain such provisions, the tribunals had no difficulty finding that Achmea cannot be extended outside of the framework in which it was rendered. Furthermore, tribunals held that the subject matter of the applicable BITs and EU law are not the same and thus not mutually exclusive.
The tribunals took the analysis a step further to explore whether the jurisdiction of the tribunal would be affected, even if the interpretation set forth in Achmea truly extended to all intra-EU BITs, as a bar for intra-EU ISDS.
Faced with assertions by respondent States and the EU Commission that the State’s consent to arbitration should be considered withdrawn as of the date of the Member States’ accession to the EU, ISDS tribunals rejected the notion of such retroactive application of the Achmea judgment to ongoing arbitral proceedings. Such an argument was raised by Croatia and the EU Commission in a series of cases brought by Austrian banks related to Croatia’s policy on the conversion of the currency of loans from Swiss Francs to Euros. These cases are particularly notable because the underlying treaty in these cases, the Austria-Croatia BIT provides that the treaty provisions shall not be applicable to the extent that they contravene EU law. As the Achmea decision forms part of the EU acquis, Croatia asserted that the ISDS clause in the BIT is incompatible with EU law, and thus should not be applicable under the applicable treaty.
The tribunal took issue with several arguments Croatia raised in support of its central jurisdictional objection. The tribunal established that the critical date for the consent to arbitration is the date of the initiation of the ICSID arbitration, which was in September of 2017, and not September 2013 (the date of Croatia’s accession to the EU), as asserted by Croatia and the EU Commission. As the consent to arbitration preceded the Achmea judgment, the tribunal held that Achmea cannot be considered “in force” as part of EU law “before it was rendered“ and that investors and States cannot be expected to anticipate “what definitive interpretations of EU law may come from the CJEU in the future.” Therefore, despite an explicit provision in the underlying BIT establishing the primacy of EU law in case of incompatibilities, the tribunal found that this does not apply to incompatibilities that post-date the consent to arbitration.
Just as in the ECT arbitrations, the tribunals did not find incompatibilities between the dispute resolution clauses in the underlying BITs with the TFEU. Furthermore, the tribunals rejected the arguments of the Respondent Member States that the January Declaration should be viewed as part of the EU acquis and thus part of the body of EU law that is applicable under the BIT, or at least as an authoritative “interpretation of the interpretation of Articles 267 and 344 of the TFEU”. Noting the much broader scope of the January Declarations than the Achmea ruling itself, and the impropriety of its retroactive effects, the tribunals held that States should not be allowed to undermine the jurisdiction of arbitral tribunals in pending cases simply by issuing joint statements.
One tribunal also indicated that Austria and Croatia found no incompatibilities of their BIT with EU law in bilateral meetings held in 2018, which contradicted Croatia’s assertions that the BIT and its ISDS clause were never meant to take effect as incompatible with EU law as of the date of Croatia’s accession to the EU.
The consistent case law illustrated above slowed down the pace of the realization of the ISDS policy objectives of the EU at the international level, despite the well-oiled machinery set in motion for this purpose. The Respondent Member States and the EU Commission were unable to persuade the ISDS tribunals that Achmea should have the effect of extinguishing the jurisdiction of arbitral tribunals established through prior consent expressed by EU Members States in BITs and the ECT, prior to the ruling itself. In no uncertain terms, as analyzed above, the tribunals found no incompatibility between EU law and the applicable treaties, under the rules of international law that applied in those cases. One of the strongest takeaways from the jurisprudence on intra-EU challenges to date is an emphasis on the distinction between the EU legal order and the international legal order in which ISDS tribunals operate.
What is the Aftermath of the Intra-EU Jurisdictional Challenges post-Achmea?
The constant flow of jurisdictional challenges and EU Commission interventions in ISDS proceedings has not resulted in the desired implementation of the Achmea ruling of the CJEU which is the final derogation of investment arbitration in intra-EU disputes. What may have come as an even more undesirable effect for the EU is the consistency and forcefulness of the decisions of arbitral tribunals faced with jurisdictional challenges based on EU law. Given that the EU has been among the most ardent critics of the perceived inconsistency and unpredictability of arbitral awards in ISDS, their efforts to suppress the jurisdiction of arbitral tribunals have allowed the emergence of a clear and steady “case law” rejecting the assertions of the retroactive applicability of the Achmea judgment to the jurisdiction of the arbitral tribunals. This applied equally for arbitrations under the ECT and intra-EU BITs.
Although the tribunals noted on several occasions that there is no system of stare decisis in investment arbitration, they proceeded to cite similar prior decisions as persuasive and consistent with the applicable norms of international law. Without questioning the effects of Achmea within the EU, the tribunals refused to accept the broad interpretations of the primacy of EU law in international matters, as asserted by the Respondent Member States and the EU Commission. The tribunals also rejected the notion that the Achmea judgment should be extended to ECT arbitrations, both based on the plain meaning analysis of the ECT itself, and the fact that the CJEU stopped short of extending the effects of Achmea to ECT arbitrations. Importantly, the tribunals took a clear stance on the assertion that the ECT was never intended to apply to intra-EU ISDS, and that the January Declarations effectively represent a unilateral modification of the ECT between EU Member States, rejecting such arguments on the basis of the VLCT. Further, the tribunals held that, even if the effects of Achmea were to extend to all BITs and the ECT, it cannot apply retroactively to annul arbitration agreements that were perfected before the CJEU issued its ruling.
The destiny of ISDS within the EU legal system seems to be sealed, considering the existing policies and the planned establishment of a standing investment court. However, the situation at the global level is much less clear and many governments have expressed their preference of a nuanced reform of the existing ISDS system. The recent case law addressing the intra-EU jurisdictional challenges has undermined the persistent criticism of inconsistency in ISDS awards, as a threat to the legitimacy of the system.
To date, the only result of the campaign against intra-EU arbitration is a steady trail of consistent case-law rejecting intra-EU jurisdictional challenges. The harmonious response of arbitral tribunals to intra-EU challenges, both before and after Achmea, has shed a different light on ISDS practice – one that is resilient and speaks in one voice under the rules of international law from which they draw their jurisdiction. There is no doubt that the existing ISDS system has reached a stage of maturity where calibrated reform could help address the real issues that have manifested over the past decades. Ironically, the EU, as the strongest advocate for the abandonment of the existing ISDS system, may be helping to make the case for the pursuance of a more balanced reform.
 Slowakische Republik v Achmea BV (‘Achmea’), Judgment of the Court (Grand Chamber) of 6 March 2018, Case C-284/16.
 Nathalie Bernasconi-Osterwalder and Lise Johnson, ‘What to Expect in the January 2020 Session of UNCITRAL Working Group III on ISDS Reform’ (IISD Investment Treaty News, 17 December 2019) <https://www.iisd.org/itn/en/2019/12/17/what-to-expect-in-the-january-2020-session-of-uncitral-working-group-iii-on-isds-reform-nathalie-bernasconi-osterwalder-lise-johnson/> accessed 10 June 2021.
 UNCITRAL Working Group III, ‘Submission from the European Union and its Member States’ (‘EU Submission’) (Thirty Seventh Session, A/CN.9/WG.III/WP.159/Add.1, 29 January 2019) 9 <https://undocs.org/en/A/CN.9/WG.III/WP.159/Add.1> accessed 10 June 2021.
 ibid 9.
 Achmea (n 1) para 48.
 EU Submission (n 3) 4.
 Michael Ostrove and Clementine Emery, ‘European Union Overview: International Arbitration Laws and Regulations 2020’ (ICLG, Augst 2020) <https://iclg.com/practice-areas/international-arbitration-laws-and-regulations/5-european-union-overview> accessed 10 June 2021.
 This article will refer to the prominent cases that provide detailed analyss of the intra-EU issues and not necessarily all of the cases in which such challenges were raised. The tribunals in all the known cases rejected the intra-EU jurisdictional challenges.
 Achmea B.V. v. The Slovak Republic, UNCITRAL, PCA Case No. 2008-13 (formerly Eureko B.V. v. The Slovak Republic).
 Slovak Republic v. Achmea B.V., Case C-284/16, Opinion of Advocate General Wathelet (19 Sept. 2017), EU:C:2018:158
 ibid para 86.
 Achmea (n 1) para 60.
 It is important to note here that the choice of law provision in the applicable BIT actually referred to the national law of the Member States that were parties to the treaty. This by definition means that the tribunals constituted under the provisions of the treaty were likely to interpret EU law. However, this is not a common practice in other intra-EU BITs. Article 8 (6) Netherlands-Slovakia BIT (1991) (terminated).
 Declaration of the Member States of 15 January 2019 on the legal consequences of the Achmea judgment and on investment protection (‘January Declaration’) <https://ec.europa.eu/info/publications/190117-bilateral-investment-treaties_en> accessed 07 June 2021.
 Ibid 3.
 Ibid 2.
 Declaration of the Representatives of the Governments of the Member States of 16 Jan. 2019 on the enforcement of the judgment of the Court of Justice in Achmea and on investment protection in the European Union (Finland, Luxembourg, Malta, Slovenia and Sweden), paras 5, 8; Declaration of the Representatives of the Government of Hungary of 16 Jan. 2019 on the enforcement of the judgment of the Court of Justice in Achmea and on investment protection in the European Union, para. 7. (‘Separate Declarations’).
 January Declaration (n 13) 3.
 Termination Agreement, recital 4, literal (a), Art. 7 (29 May 2020), https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:22020A0529(01)&from=EN (accessed 8 June 2020).
 Sunset clauses are treaty provisions that extend the effects of the provisions of the treaty for a certain period of time after the termination of the treaty (in most cases from fifteen to thirty years).
 The Termination Agreement defines “Pending Arbitration Proceedings”as !any Arbitration Proceedings initiated prior to 6 March 2018 and not qualifying as Concluded Arbitration Proceedings, regardless of their stage on the date of the entry into force of this Agreement.“ Terminaton Agreement (n 19) art 1.
 Termination Agreement (n 18) art 9(2) and 10 (a).
 ibid art 9(4).
 For a detailed critical analysis of the Termination Agreement, see Gustavo Adolfo Guarin Duque, ‘The Termination Agreement of Intra-EU Bilateral Investment Treaties: A Spaghetti-Bowl with Fewer Ingredients and More Questions’, in Maxi Scherer (ed), Journal of International Arbitration, (Kluwer Law International 2020, Volume 37 Issue 6) 797 – 826.
 Termination Agreement (n 18) art 6 and 8(2).
 Submission (n 3) 4.
 Masdar Solar & Wind Cooperatief U.A. v. Kingdom of Spain, ICSID Case No. ARB/14/1
 Eskosol S.p.A. in liquidazione v. Italian Republic, ICSID Case No. ARB/15/50
 Vienna Convention on the Law of Treaties, art 31
 UNCTAD, IIA Issues Note, Fact Sheet on Intra-European Union Investor-State Arbitration Cases, 8 (United Nations, December 2018).
 Eskosol (n 31) para 87., Blusun S.A., Jean-Pierre Lecorcier and Michael Stein v. Italian Republic, ICSID Case No. ARB/14/3, Award, 27 December 2016 para 283.
 Eiser Infrastructure Limited and Energía Solar Luxembourg S.à r.l. v. Kingdom of Spain, ICSID Case No. ARB/13/36 para 94, Eskosol (n 31) para 93, Charanne B.V. and Construction Investments S.A.R.L. v. The Kingdom of Spain, SCC Case No. V062/2012 para 427-431, Masdar (n 27) para 318-323
 Prior to Achmea:; Eiser (note 36) para 186; Novenergia II – Energy & Environment (SCA) (Grand Duchy of Luxembourg), SICAR v. Kingdom of Spain, SCC Arbitration 2015/063 para 454; Vattenfall AB and others v. Federal Republic of Germany, ICSID Case No. ARB/12/12, Decision on the Achmea Issue para 202, and others.
 RREEF Infrastructure (G.P.) Limited and RREEF Pan-European Infrastructure Two Lux Siu.I. v. Spain, ICSID Case No. ARB/13/30, Decision on Jurisdiction of 6 June 2016, para. 85; Eiser Infrastructure Ltd. & Energia Solar Luxembourg v. Spain, ICSID Case No. ARB/13/36, Award of 4 May 2017, para. 187; Blusun para 280
 J Robert Basedow, ‘The Achmea Judgment and the Applicability of the Energy Charter Treaty in Intra-EU Investment Arbitration’ (Journal of International Economic Law, Volume 23, Issue 1, March 2020) 271–292.
 Eiser (n 36) paea 183 cited in Eskosol (n 31) para 92.
 Vattenfall (n 37) para 221, Eskosol (n 31) paras 148-151.
 Eskosol (n 31).
 Strabag SE, Raiffeisen Centrobank AG and Syrena Immobilien Holding AG v Republic of Poland (ICSID Case No. ADHOC/15/1)
 Vattenfal (n 37) paras 114-116, Greentech Energy Systems A/S, et al v. Italian Republic, SCC Case No. V 2015/095 para 218, Eiser (n 369 para 197, Eskosol (n 31) para 114.
 RREEF (n 38) paras 75-77; Antin Infrastructure Services Luxembourg S.à.r.l. and Antin Energia Termosolar B.V. v. Kingdom of Spain, ICSID Case No. ARB/13/31 para 215; Watkins Holdings S.à r.l. and others v. Kingdom of Spain, ICSID Case No. ARB/15/44 paras 221-25
 Energy Charter Treaty art 16.
 Eskosol (n 31) paras 207-227; InfraRed Environmental Infrastructure GP Limited and others v. Kingdom of Spain, ICSID Case No. ARB/14/12 para 267.
 Landesbank paras 165-166.
 InfraRed (note 47) para 267; Eskosol (n 31) paras 207-227.
 Which was the case in the BIT between the Netherlands and Slovakia, underlying the dispute in the Achmea case.
 The relevant provision of the Netherlands-Slovakia BIT provided the following: Article 8, para 6 The arbitral tribunal shall decide on the basis of the law, taking into account in particular though not exclusively: the law in force of the Contracting Party concerned; the provisions of this Agreement, and other relevant Agreements between the Contracting Parties; the provisions of special agreements relating to the investment; the general principles of international law. <https://investmentpolicy.unctad.org/international-investment-agreements/treaty-files/2080/download> accessed 11 June 2021.
 CEF Energia B.V. v. The Italian Republic, SCC Case No. V 2015/158).
 Sodexo Pass International SAS v Hungary (ICSID Case No. ARB/14/20) (reported); Juvel Ltd. & Bithell Holdings Ltd. v. Poland, ICC, Case 19459/MHM; UP (formerly Le Chèque Déjeuner) and C.D Holding Internationale v. Hungary, ICSID Case No. ARB/13/35.
 Raiffeisen Bank International AG and Raiffeisenbank Austria v Republic of Croatia (ICSID Case No. ARB/17/34) para 230.
 Article 11 (2) of the Austria-Croatia BIT provides the following: The Contracting Parties are not bound by the present Agreement insofar as it is incompatible with the legal acquis of the European Union (EU) in force at any given time. <https://investmentpolicy.unctad.org/international-investment-agreements/treaty-files/180/download> accessed 11 June 2021.
 UniCredit Bank Austria AG and Zagrebačka Banka dd v Republic of Croatia (ICSID Case No. ARB/16/31) – pending case, decision unavailable and Raiffeisen Bank International AG and Raiffeisenbank Austria v Republic of Croatia (ICSID Case No. ARB/17/34); Addiko Bank AG and Addiko Bank d.d. v. Republic of Croatia (ICSID Case No. ARB/17/37).
 ibid para 243.
 ibid para 227.
 Addiko Bank (n 56) paras 291-297 ; UP (n 53) para 248.
 ibid para 285.
 Addiko Bank (n 56) para 290, Eskosol (n 31) para 226.
 The tribunal also addressed the encouragement expressed in Croatia’s 2005 Accession Agreement (Article 85) with the EU to „expand its BITs with EU Member States“. ibid paras 235-244.
 Eskosol (n 31) para 146, Infrared (n 47) para 206.
 United Nations Commission on International Trade Law Working Group III (Investor-State Dispute Settlement Reform),’ Possible reform of investor-State dispute settlement (ISDS)’ (Note by the Secretariat, Thirty-eight session, 30 July 2019 <https://undocs.org/en/A/CN.9/WG.III/WP.166> accessed 12 June 2021.
The author is the country coordinator of a regional project dedicated to ISDS reform in the Western Balkans, the Research Director of Arbitrator Intelligence, and an adjunct lecturer at the International University of Sarajevo Faculty of Law.