Investor-State Dispute Settlement is currently facing a legitimacy crisis which threatens to rattle the very foundations of the system. It is suggested this crisis can be divided in two: a procedural crisis, which can be addressed by reform, and a substantive crisis, which threatens the existence of the entire regime. This article focuses on the deeper substantive crisis caused by the problem of reverse discrimination. Specifically, it engages with constitutional terms of analysis to address the way in which reverse discrimination undermines national constitutional stability. It analyses exactly why the affront to constitutional stability is currently becoming particularly hard to bear for nation states. The conclusion is that the substantive legitimacy crisis faced by investment treaty law can only be addressed by a comprehensive repeal of the system.
The EU has failed to reach an agreement with the United States on the Transatlantic Trade and Investment Partnership (TTIP) in large part because of its Investment Chapter: neither party could accept that foreign investors would be subject to a different set of rights than domestic companies.1 It is patently clear that the legitimacy of Investor-State Dispute Settlement (ISDS) is currently under threat.2 The first point is that the ISDS system currently faces two separate, but related, legitimacy crises. The first crisis, of procedural legitimacy, is strictly internal to the system – it stems from issues related to the way in which ISDS is dispensed. Importantly, these issues can be addressed by reform without significantly overhauling the system. The second, substantive legitimacy crisis, is exogenous to the workings of the system – it is rooted in the very logic of investment treaty law. The focus of this article is on this second, existential, challenge to the system. An insight will be provided into the issue of ‘reverse discrimination’, a practice through which foreign investors are able to use bilateral investment treaties (BITs) to obtain a different treatment than national companies. The existing literature on this topic describes the problems created by reverse discrimination in rather broad terms: reverse discrimination is accused of generally ‘undermining democratic accountability’ and ‘threatening legitimacy’.3 The central purpose of the present article is to couch the issue of reverse discrimination in much more specific constitutional terms. As such, we will argue why the very logic of investment treaty law compromises constitutional commitments on the national level. We will also analyse why exactly this birth defect is now emerging as particularly unpalatable for sovereign states. This will lead to the unassailable conclusion that abandoning the ISDS system is necessary in order to protect national constitutional stability.
1. Explaining the two aspects of the legitimacy crisis
It is widely understood that the ISDS system is currently plunged in a profound legitimacy crisis.4 The United Nations Commission on International Trade Law (UNCITRAL) has formerly recognized this in asserting the pressing need for reform.5 Its most recent Working Paper (2020) identified three proposals: (i) the potential introduction of a ‘stand-alone review or appellate mechanism’; (ii) the creation of a ‘multilateral investment court’; and (iii) a fairer ‘selection and appointment of arbitrators and adjudicators’.6 These proposals recognise that ISDS is undergoing a procedural legitimacy crisis, one which is strictly internal to the system. Their aim is therefore to reform ISDS from the inside. Importantly, the UNCITRAL diagnoses a strictly procedural crisis: they do not call for integral repeal of the system, but rather, seek to reform a number of its procedures.
Kelsey et al. note that a narrow focus on procedural issues carries the risk of ignoring the substantive challenges to the system – i.e. those which pose an existential threat to ISDS.7 To a certain extent, it is not a surprise that UNCITRAL refuses to address substantive critiques of the system. Indeed, it is uniquely set up to look at the system from an internal perspective. The Guide to UNCITRAL published by the UNCITRAL secretariat states that part of the Commission’s mandate is to promote ’wider participation in existing international conventions and wider acceptance of existing model and uniform laws’.8 As a reform body, it is engineered to consider only issues of procedure, without ever challenging the logic of ISDS itself.
Our contention is that a wider substantive legitimacy crisis dwarfs the narrow procedural crisis addressed by UNCITRAL. Specifically, the issue of reverse discrimination threatens to shake the constitutional foundations of sovereign states. The remainder of this article focuses on this broader, existential challenge, and explores why the system must therefore be overturned.
2. The substantive aspect of the legitimacy crisis: how reverse discrimination threatens constitutional stability
a) How does ISDS entail reverse discrimination?
Originally, the vast majority of Bilateral Investment Treaties (BITs) were signed between a developed, capital-exporting country and a developing, capital-importing country.9 As Jandhyala et. al note, during the first wave of BIT signings, ’the adoption of a BIT helped reassure foreign investors by offsetting weak and unstable domestic institutions in host countries.10 Foreign investors would be encouraged to invest in developing countries, emboldened by the certainty that their investment would not be subjected to host country legal institutions, and therefore not expropriated or confiscated.11 BITs were thus a way to hedge against political risk through law. Legally, these treaties were always reciprocal, but investment flows almost never came towards the developed country, which meant that policies in developed countries were very rarely challenged in investment arbitrations. As Mann demonstrates, the bilateral dimension of BITs was initially included only as a ceremonial recognition of the developing country’s sovereignty – in this sense, reciprocity was ’a matter of prestige [rather] than reality’.12 This changed when Free Trade Agreements including investment chapters (such as NAFTA and the Energy Charter Treaty13 were concluded between countries with equally strong commitments to democracy and the rule of law. Suddenly, it became evident that foreign investors could challenge national policies in democratic states. Specifically, this entails that a foreign investor is not subject to the same regime as a national investor: where a national investor has no choice but to abide by national regulations, a foreign investor is able to challenge certain measures as per the terms of the BIT. This epitomises the problem of ‘reverse discrimination’ which exists in favour of foreign investors.
b) Reverse discrimination – the threat to constitutional stability
Much of the existing literature describes the problems raised by reverse discrimination in rather broad terms: reverse discrimination is accused of generally ‘undermining democratic accountability,14 ’unduly limiting the policy space of signatory governments15 and ‘threatening legitimacy’.16 The purpose of the present article is to frame the issue of reverse discrimination in much more specific constitutional terms. In doing so, we will reach a clearer understanding of why ISDS, and more specifically reverse discrimination, poses an affront to constitutional stability.
(i) The framework of analysis
As Halberstam sets out, a nation state is a social artefact – its inherent purpose is to further the needs and aspirations of its constituents.17 From this premise, Dawson and De Witte have concluded that a polity is ’only stable and legitimate, then, if it structurally incorporates and reflects the values that ”matter” to its constituents’.18 Accordingly, durable legitimacy requires a dual commitment to ‘self-determination’. The first commitment is to ‘political self-determination’: it requires having an institutional mechanism which mediates between competing visions within the polity.19 This process, which invites all contrasting views to come together in deciding on policy outcomes, enables these very outcomes to be shrouded in a certain legitimacy. The second commitment is to ensure that, from a legal perspective, legal actors are free and equal.20
We propose to assess ISDS in light of this theoretical framework set out by Dawson and De Witte. We hope to demonstrate the extent to which the very logic of the system, which brings about reverse discrimination, undermines the two central tenets of stability and legitimacy in a nation state. Therein, we contend, lies the real reason for the ISDS system’s legitimacy crisis.
(ii) How does reverse discrimination undermine states' political ownership over laws and regulations?
Through the problem of reverse discrimination, ISDS both challenges and undermines states’ ability to decide upon their own rules and regulations. This is epitomised, firstly, by the fact that certain ISDS proceedings result in states having to pay out of public funds for democratically reached policy choices. Kelsey et al. note that this is perceived as particularly problematic when pay-outs are destined to large transnational corporations and redirected away from spending on education and healthcare.21 In many situations, this problem is amplified by the lack of transparency that covers many investment arbitrations.22
A number of states have voiced their concerns on this very matter. The South African Government, in their proposal to the UNCITRAL, highlighted that the ISDS system creates a framework where ’the investors’ property and contractual rights supersede public interest and public needs’.23 Specifically, they raised the point that the system is ’detrimental to public budgets, regulations in the public interest, democracy and the rule of law’.24 Similar concerns have also been echoed by Brazil and Indonesia before the UNCITRAL.25
The paradigm example of this problem was demonstrated by the Vattenfall ICSID decision, where a Swedish company, having invested in nuclear energy in Germany, was successful in obtaining compensation for Germany’s political decision to exit from nuclear energy.26 Against the backdrop of the 2011 nuclear disaster in Fukushima (Japan), Germany reached a broad consensus to amend the Atomic Energy Act,27 and thereby abandon the use of nuclear energy by 2022.28 In conjunction with this amendment, seven further legislative proposals from the federal government were adopted, aiming to bring about a new era of energy policy.29 Germany’s decision was clearly the outcome of a concerted process. The ISDS system thus seems to make countries pay for reasonable democratic choices. This case caused specific backlash in German society because Vattenfall was able to circumvent three levels of jurisdiction: national, EU and ECHR, two of which Germany shared with Sweden.
Secondly, the very prospect of being challenged before an investment tribunal has chilling effects on sovereign states’ ability to exercise their authority, an effect which goes beyond the fiscal cost of defending disputes. Indeed, the investment regime, by enabling foreign companies to challenge national measures before an investment tribunal, causes chilling effects both directly (when the threat of investment dispute deters government action) and indirectly (when a country may decide to refrain from adopting a specific measure because it is already involved in numerous disputes).30 This may lead to a ‘systemic’ chill where policy-making incorporates an assessment of the potential risks of an investment dispute.
One may counter the preceding argument by highlighting that sovereign states are not coerced into entering BITs. As such, being bound by BITs would equally be an expression of national political will, and undermining these international agreements would also amount to thwarting political ownership over decision-making.31 This argument would be defensible if sovereign states knew exactly the scope of the consequences derived from signing up to BITs. However, as noted above, where legal reciprocity was always a feature of BITs, the factual and economic reciprocity of investment flows has only emerged in recent years.
This is in part due to the economic emergence of developing economies which, in turn, started issuing foreign direct investments.32 The UNCTAD studied this issue, noting that where developing economies emitted 14% of the world’s share of FDI in the world in 1995, they represented 21% of the world share in 2009,33 a trend that has since continued to rise. In 2014, developing and transitioning economies accounted for 38% of the world share in FDI.34 A significant portion of this FDI is in fact directed towards developed economies.
In correlation to this increase, developing countries have appeared with increasing frequency before ISDS tribunals in investment disputes. Whereas in 2012 only 11% of claimants hailed from developing or transition economies,35 the number has increasingly surged, amounting to 32% in 2018.36 Importantly, many of these cases have been brought against developed economies. In an era where Portugal has actively encouraged investment from Angola into its public utilities sector,37 the prospect of developed states defending their policies before investment tribunals has become increasingly likely.
But the emergence of legal reciprocity in investment flows is also attributable to developed states inadvertently agreeing upon investment chapters among themselves. The case in point is the Energy Charter Treaty (ECT),38 which was initially viewed as a multilateral treaty safeguarding EU investments in Eastern European states.39 As Alvarez notes, after more than a decade the EU realised that the ECT could be used by EU companies to protect foreign investments in fellow member states.40 This was particularly shocking as it amounted to circumventing the common EU level investment legislation.41
Historical contingency played a significant role in creating this rare occurrence in international law – by no means do sovereign states regularly commit such consequential errors when reaching international agreements. The Lisbon Treaty, concluded in 2009, provided that all intra-EU investment disputes would be submitted to the Court of Justice of the European Union.42 As such, it had the effect of terminating many pre-existing intra-EU BITs, given their incompatibility with EU law.43 The Lisbon Treaty, however, was unable to terminate the ECT, which had entered into force in 1998, specifically because it was not a strictly intra-EU BIT. Indeed, the ECT is a binding international treaty that not only includes all of the EU Member States, but also a number of third states.44 This seemingly anecdotal legal episode has since yielded tremendous consequences for the ISDS system. The UNCTAD estimates that the ECT was invoked in 20% of all investor-state arbitrations world-wide,45 making it the single most frequently invoked mechanism for ISDS.46 Of these ECT disputes to date, 64% were strictly intra-EU.47
What this particular situation reveals is the extent to which states sometimes cannot anticipate the full ambit of international mechanisms to which they subscribe. In any case, it is manifest that the ISDS system, through reverse discrimination, challenges sovereign states’ political ownership over their laws and regulations. Therefore, the ISDS system undermines a core feature of stable constitutions.
(iii) How does reverse discrimination undermine freedom and equality amongst actors?
As Jan Kleinheisterkamp argues, ISDS grants greater rights to foreign investors than to national investors: this undermines states’ democratic commitment to equality of rights, and means that domestic companies do not have the same freedom to act as their domestic counterparts.48 The ‘greater rights’ granted to foreign investors manifest themselves in several ways: (i) they allow the foreign investor to explore an avenue for redress which the national investor cannot explore, (ii) they enable foreign investors to claim limitless awards by circumventing the limits that operate on compensation in domestic courts and (iii) they also enable foreign investors to enter into contracts with states without facing the same political risk that a national company would face. Kelsey et al. note that this inequality of rights amongst economic actors significantly distorts market relations in favour of foreign companies: having the ISDS outlet means that the amount of risk incorporated in their investment decisions is largely inferior compared to their domestic counterparts.49
In an attempt to counter this observation, Christian Riffel, amongst others, posits that ISDS does not undermine states’ commitments to equality before the law.50 Two broad types of arguments are made to this end.
The first line of counter-argument
The first line of argument suggests that applying the same rules to national and foreign investors is not desirable since they are in materially different positions to start off with.51 It therefore sees carving out a specific regime for foreign investors as a way of balancing out the starting positions. An example of this initial difference is the specific due diligence imposed on foreign companies by acts such as the Enterprise Act,52 when entering the UK market.
The investment protection system seeks to eliminate this initial difference by implementing standards in international investment treaties which are ’functionally comparable to constitutional guarantees and administrative law principles at the domestic level’.53 Kleinheisterkamp refers to this as following a ‘logic of substitution’.54 Foreign investors are not subjected to national judicial procedures which may discriminate against them unfairly – rather, the national procedures are ‘substituted’ by an international procedure which emulates the way national procedures would work for domestic companies. This artificial mechanism thereby intends to cut all discrimination out of the process.
In practice, however, carving out a separate regime for foreign investors does not necessarily have the desired effect of replicating national procedures. One reason for this points to the multitude of different national procedures, and the impossibility for the international regime to reflect all of these accurately. Indeed, each domestic jurisdiction strikes its own subtle balance between ‘the private interests of investors and the public interests of host states.’55 The provisions encapsulated in BITs are unable to reflect these specific balances because they frame standards of protection in general and open-textured language. It is almost a trite fact that standards of judicial review such as ‘fair and equitable treatment’, ‘full protection and security’ and ‘indirect expropriation’ are highly vague and can be given different content depending on the case at hand, and the panel hearing it. In the Suez case, the UNCITRAL reflected this point by highlighting that the ‘ordinary meaning’ of the ‘fair and equitable treatment’ standard can only be defined by terms of ‘almost equal vagueness’.56 This mismatch between ‘general’ standards in BITs and ‘specific’ balances on the national level reveals the practical impossibility for investment treaty law to satisfy the ‘logic of substitution’ that forms its guiding principle.
A second related reason why carving out a separate regime for foreign investors through BITs does not effectively replicate national procedures is that at times, investment treaty law creates more favourable conditions for foreign investors than would be available under national law for domestic companies. This problem of ‘reverse discrimination’ is a direct consequence of the aforementioned vagueness of BIT standards, and of the important discretion that investment tribunals have in ascribing content to these provisions. Because of this latitude, individual tribunals can confer awards to foreign investors where equivalent awards would not be available to domestic companies appearing before national courts. The case in point is Vattenfall:57 had Vattenfall been a domestic company, it would plainly have not been able to recoup its investment. Importantly, the decision in Vattenfall does not represent a one-off anomaly but falls within a broader trend. A couple of salient examples are the cases of Masdar v. Spain58 and Occidental Petroleum v. Ecuador59, which replicate the Vattenfall format, enabling foreign investors to benefit from ISDS in a way which was unavailable to domestic companies.
This is not to say that investment treaty law systematically creates inverse discrimination in favour of foreign investors – in many occasions, international investment tribunals are able to track national procedures. In this sense, Lowe is not exactly right when he asserts that ’the consequence is plain and inescapable. BITs give foreign investors wider rights than nationals possess’.60 Rather, BITs create the potential for foreign investors to have wider rights than nationals possess. However, what matters for the purposes of our analysis is that this potential exists – and that this potential sometimes comes to fruition. Indeed, what this demonstrates is that the separate regime for foreign investors does not, and cannot, successfully and systematically replicate national procedures. The potential for reverse discrimination inherent to investment treaty law therefore means that it does not, as Riffel suggests, successfully correct the initial imbalance between national and foreign investors. Their unequal position in front of the law is maintained.
Moreover, this line of argument which supports the separate system of investment treaty law for foreign investors is also flawed because it does not account for the idea that a company’s choice to enter a foreign market carries an inherent responsibility to adhere by domestic laws.61 These are considerations that should be internalised by companies when they decide to make a foreign direct investment.
The second line of counter-argument
The second line of argument posits that in practice, there is no material difference between the treatment of foreign companies under investment treaty law and that of domestic companies under domestic law, and therefore it would be erroneous to view investment treaty law as creating inequality.62 The example given for this point is that ’domestic law may make available the same remedies as an international investment agreement’.63 Viewed alongside the first line of argument, it seems that supporters of ISDS are trying to have it both ways. Riffel stresses that investment treaty law both creates and doesn’t create inequality.64 More importantly, as Kleinheisterkamp highlights, although in theory domestic remedies do exist, in practice the domestic paths to accessing such remedies are much more saturated than they are for investment tribunals.65 As such, it would be plainly incorrect to assert that both investment tribunals and domestic courts lead to equal outcomes.
It is therefore clear that ISDS, structured to create reverse discrimination, compromises national constitutional commitments to freedom and equality of all actors before the law.
(iv) Constitutional compromising: why now?
What transpires from this analysis is that the very logic of investment treaty law, which carves out a different regime for foreign investors, undermines the central tenets of a stable and legitimate constitution within a polity: (i) political ownership over common rules and (ii) freedom and equality of all actors before the law. The ISDS’s substantive legitimacy crisis stems from its inherent incompatibility with the core constitutional values within states.
Yet, one may ponder why it is only now that the birth defects in the system are coming to the surface and creating a substantive legitimacy crisis. The first reason, detailed above, is that the legal reciprocity of BITs is only now accompanied by reciprocal investment flows. This is the case between developed and developing nations, but also between developing nations themselves.66 This trend has been accelerated by recent cases, such as Masdar v Spain,67 where an increasingly broad interpretation of ‘investment’ has been adopted. Whereas ‘investment’ used to be reserved for significant transnational acquisitions of property, the term now seems vague enough to capture ordinary commercial transactions.68 Indeed, as Tim Samples demonstrates, economic and technological developments have changed the nature of investments, and therefore changed the definition of ‘investment’.69 Early generation BITs could not envisage, in their drafting, the current scope of investment treaty law.70
The second reason is that a number of landmark cases in the last few decades have shown that investment treaty law is being exploited by Multinational Corporations (MNCs) to avoid accountability in host states. One such case is Methanex Corporation v. the United States which raised this point in light of environmental rules.71 In the late 1990s, a Canadian investor sued the United States because California had banned certain additives to car fuel for the protection of the environment. The idea that a foreign company could sue the United States because California was trying to protect its environment and public health caused a huge uproar in the United States – the matter was hotly debated by the House of Representatives.72 Although in this case the investment tribunal ruled in favour of the United States, it opened the floodgates to foreign investors challenging domestic laws in ISDS. A number of more recent cases have been won by investors challenging national environmental regulations,73 but also challenging regulations in a host of other policy areas. These include cases on essential services,74 financial stability,75 and development and industrial policy.76 Such decisions have, in the past decade, increased attention on the investment treaty regime’s role in undermining national accountability. Doing so has revealed the substantive challenges to the system’s structural legitimacy.77
The ISDS system’s substantive legitimacy crisis is caused by the inherent logic of the system itself – for this reason, it simply cannot become legitimate. Threatening to increasingly undermine constitutional commitments at the national level, it is urgent for the regime as a whole to be repealed. Only through such drastic measures will the substantive challenges posed by ISDS be addressed. The EU has started to realise the extent of the problem posed by reverse discrimination. Following the ECJ ruling in Achmea,78 where it was declared that Intra-EU BITs were contrary to EU law, 23 EU Member states (all except Austria, Ireland, Finland and Sweden) have signed on 5 May 2020 the ‘Agreement for the Termination of Bilateral Investment Treaties between the Member States of the European Union’. What such an agreement will reap is uncertain, but its existence certainly does signal a formal recognition of the substantive challenges contained in the ISDS regime.
I would like to extend my thanks to the LSE Law Review editorial board for their comments on an earlier draft. All errors remain my own.
 T. Dietz, M. Dotzauer and E. Cohen, ‘The Legitimacy Crisis of Investor-State Arbitration and The New EU Investment Court System’ (2019) 26 Review of International Political Economy 749, 759.
 UNCITRAL, ‘Possible future work in the field of dispute settlement: Reforms of investor-State dispute settlement (ISDS): Note by the Secretariat’ (20 April 2017) A/CN.9/917 (UNCITRAL Secretariat Note, A/CN.9/917), para. 12. See also UNCITRAL Working Group III ‘Possible reform of investor-State dispute settlement (ISDS): Note by the Secretariat’ (18 September 2017) A/CN.9/WG.III/WP.142 (Note by the Secretariat, WP.142), paras. 45-47.
 J. Kelsey, D. Schneiderman and G. Van Harten, ‘Phase 2 Of The UNCITRAL ISDS Review: Why ‘Other Matters’ Really Matter’ (2019) SSRN Electronic Journal 1, 1.
 UNCITRAL, ‘Possible future work in the field of dispute settlement: Reforms of investor-State dispute settlement (ISDS): Note by the Secretariat’ (20 April 2017).
 UNCITRAL, ‘Possible future work in the field of dispute settlement’ (n 2) 15.
 UNCITRAL Secretariat, ‘A Guide To UNCITRAL: Basic Facts About the United Nations Commission on International Trade Law’ (United Nations 2013).
 S. Jandhyala, W. Henisz, and E. Mansfield, ‘Three Waves of Bits’ (2011) 55 Journal of Conflict Resolution 1047, 1049.
 ibid 1048.
 See E. Neumayer, ‘Self-Interest, Foreign Need, and Good Governance: Are Bilateral Investment Treaty Programs Similar to Aid Allocation?’ (2006) 2 Foreign Policy Analysis 245, 247; J.W. Salacuse and N.P. Sullivan ‘Do BITs Really Work?: An Evaluation of Bilateral Investment Treaties and Their Grand Bargain’ (2005) 46 Harvard International Law Journal 67, 73.
 F. A. Mann, ‘British Treaties for the Promotion and Protection of Investments’  British Year Book of International Law 241.
 Energy Charter Treaty, Dec. 17, 1994, 2080 U.N.T.S. 95.
 M. Waibel, A. Kaushal, K. Chung & C. Balchin, “The Backlash Against Investment Arbitration: Perceptions and Reality” in M. Waibel, A. Kaushal, K. Chung & C. Balchin (eds), The Backlash Against Investment Arbitration (London: Kluwer Law International 2010), 3.
 M. Bronckers, ‘Is Investor–State Dispute Settlement (ISDS) Superior to Litigation Before Domestic Courts? An EU View on Bilateral Trade Agreements’ (2015) 18 J. INT’L ECON. L. 655, 672–74, 677.
 See J. Kelsey, D. Schneiderman and G. Van Harten, ‘Phase 2 Of The UNCITRAL ISDS Review: Why ‘Other Matters’ Really Matter’  SSRN Electronic Journal 1, 1;; L. Johnson & Brooke Guven, The Settlement of Investment Disputes: A Discussion of Democratic Accountability and the Public Interest, (2017); International Institute for Sustainable Development, ‘Assessing The Impacts Of Investment Treaties: Overview Of The Evidence’ (2017).
 M. Halberstam, Totalitarianism and the Modern Conception of Politics (New Haven, CT, Yale Univeristy Press 1999) 17.
 M. Dawson and F. de Witte, ‘Constitutional Balance In The EU After The Euro-Crisis’ (2013) 76 The Modern Law Review 817, 819.
 UNCITRAL, ‘Possible future work in the field of dispute settlement’ (n 2) 12.
 R. Moloo and J. Jacinto, ‘Environmental and Health Regulation: Assessing Liability Under Investment Treaties’ (2011) 1-65 Berkeley Journal of International Law, 43.
 UNCITRAL, ‘Possible future work in the field of dispute settlement (ISDS): Submission from the Government of South Africa: Note by the Secretariat’ (17 July 2019) A/CN.9/WG.III/WP.176, para 7.
 ibid para 11.
 See UNCITRAL, ‘Possible future work in the field of dispute settlement (ISDS): Submission from the Government of Brazil: Note by the Secretariat’ (28 March 2019) A/CN.9/WG.III/WP.171; UNCITRAL ‘Possible future work in the field of dispute settlement (ISDS): Submission from the Government of Indonesia: Note by the Secretariat’ (29 October 2018) A/CN.9/WG.III/WP.156.
 Vattenfall AB and others v. Germany. ICSID Case No. ARB/12/12.
 The Thirteenth Amendment to the Atomic Energy Act (13. AtGÄndG v. 31.07.2011, BGBl I S. 1704 (No. 43)) came into effect on August 6, 2011.
 Bernasconi-Osterwalder N, and Tamara Hoffmann R, ‘The German Nuclear Phase-Out Put To The Test In International Investment Arbitration? Background To The New Dispute Vattenfall V. Germany (II)’ (2012) The International Institute for Sustainable Development 1, 2.
 UNCITRAL, ‘Possible future work in the field of dispute settlement’ (n 2) 11.
 See L. Poulsen and E. Aisbett, ‘When the Claim Hits: Bilateral Investment Treaties and Bounded Rational Learning’ (2013) 65 World Politics 273.
 UNCTAD, ‘World Investment Report 2011, Non-Equity Modes Of International Production And Development’ (UNITED NATIONS PUBLICATION 2010) https://unctad.org/system/files/official-document/wir2011_en.pdf accessed 15 January 2021. FDI distributions by developed and developing countries, in US$ Billion, and % participation.
 UNCTAD, ‘World Investment Report 2020, Non-Equity Modes Of International Production And Development’ (UNITED NATIONS PUBLICATION 2020).
 UNCTAD, ‘Fact Sheet on Investor-State Dispute Settlement Cases in 2018’ (May 2019) IIA Issues Note.
 UNCTAD, ‘Latest Developments in Investor-State Dispute Settlement’ (April 2012) IIA Issues Note.
 Peter Wise, ‘Portugal appeals to Angola for funds’ Financial Times (Lisbon, 17 November 2011) https://www.ft.com/content/9c1f123e-1132-11e1-ad22-00144feabdc0 accessed 20 February 2021 .
 Energy Charter Treaty (opened for signature 17 December 1994, entered into force 16 April 1998) (ECT).
 S.H. Ng, ‘What is the future of the Energy Charter Treaty following the termination of intra-EU BITs in a post-Achmea era?’ (Working Paper) 6.
 G.M. Alvarez, ‘Redefining the Relationship Between the Energy Charter Treaty and the Treaty of Functioning of the European Union: From a Normative Conflict to Policy Tension’ (2018) 33 I.C.S.I.D. REV. 560, 562 (2018).
 Case C-284/16, Slowakische Republik v Achmea BV, 19 September 2017 (case not yet reported, ECLI:EU:C:2017:699), Opinion of Advocate General Wathelet.
 Treaty on the Functioning of the European Union, art. 344.
 UNCITRAL, ‘Possible future work in the field of dispute settlement’ (n 2) 561.
 ibid 562.
 United Nations Conference on Trade & Dev., Investor-State Dispute Settlement: Review of Developments in 2017, in 2 INT’L INV. AGREEMENTS ISSUES NOTE 1, 2 (2018), https://unctad.org/en/PublicationsLibrary/diaepcbinf 2018d2_en.pdf.
 A. Lacson, ‘What Happens Now? The Future of Intra-EU Investor-State Dispute Settlement Under the Energy Charter Treaty’ (2019) 51 N.Y.U. J. Int’l L. & Pol. 1327, 1331.
 J. Kleinheisterkamp, ‘Investment Treaty Law And The Fear For Sovereignty: Transnational Challenges And Solutions’ (2015) 78(5) The Modern Law Review 793, 797.
 UNCITRAL, ‘Possible future work in the field of dispute settlement’ (n 2) 8.
 C. Riffel, ‘Does Investor-State Dispute Settlement Discriminate Against Nationals?’ (2020) 21 German Law Journal 197.
 ibid 217.
 Enterprise Act 2002.
 S. W. Schill, International Investment Law and Comparative Public Law (Oxford: OUP, 2010) (ILL and Comparative Public Law), 28.
 J. Kleinheisterkamp, ‘Investment Treaty Law and the Fear for Sovereignty: Transnational Challenges and Solutions’(2015) 78(5) MLR 793, 811.
 J. Kleinheisterkamp, ‘Investment Treaty Law and the Fear for Sovereignty: Transnational Challenges and Solutions’(2015) 78(5) MLR 793, 820.
 Suez, Sociedad General de Aguas de Barcelona SA and InterAguas Servicios Integrales del Agua SA v Argentine Republic ICSID Case No ARB/03/17, Decision on Liability of 30 July 2010 at . See also Saluka Investments BV v Czech Republic (UNCITRAL), Partial Award of 17 March 2006 at .
 Vattenfall AB and others v. Germany. ICSID Case No. ARB/12/12.
 Masdar Solar & Wind Cooperatief U.A. v. The Kingdom of Spain. ICSID Case No. ARB/14/1.
 Occidental Petroleum Corporation and Occidental Exploration and Production Company v. The Republic of Ecuador. ICSID Case No. ARB/06/11.
 V. Lowe, ‘Changing Dimensions of International Investment Law’ (2007) Oxford Legal Studies Research Paper No. 4/2007, 49.
 UNCITRAL, ‘Possible future work in the field of dispute settlement’ (n 2) 8.
 See M. Paparinskis, ‘Investors’ Remedies Under EU Law and International Investment Law’ (2016), 17 J. World Inv. & Trade 919, 940–41 (denying the commensurability of remedies under domestic and international investment law).
 Slowakische Republik (n 41) 212.
 The Thirteenth Amendment to the Atomic Energy Act (n 28).
 Masdar Solar & Wind Cooperatief U.A. v. The Kingdom of Spain. ICSID Case No. ARB/14/1.
 See Scope and Definition 9-10 (2011), UNCTAD, http://unctad.org/en/Docs/diaeia20102_en.pdf (arguing for greater precision in the definition of investment).
 T. Samples, ‘Winning and Losing In Investor-State Dispute Settlement’ (2019) 56 American Business Law Journal 138.
 L. Wells, ‘The Emerging Global Regime for Investment: A Response’, (2010) 52 Harvard International Law Journal Online 42, 52.
 Methanex Corporation v United States, Final Award on Jurisdiction and Merits, (2005) 44 ILM 1345, Inside US Trade, 19 August 2005, 12, IIC 167 (2005), 3rd August 2005, Ad Hoc Tribunal (UNCITRAL).
 B. Legum, ‘Nafta Chatper Eleven Arbitral Tribunal: Methanex Corporation v United States of America, Final Awar on Jurisdiction and Merits’, (2005) 44(6) International Legal Materials 1343.
 See Abengoa S.A. y COFIDES S.A. v. United Mexican States, ICSID Case No. ARB(AF)/09/2, Award (April 18, 2013); William Ralph Clayton, William Richard Clayton, Douglas Clayton, Daniel Clayton and Bilcon of Delaware, Inc. v. Canada, Award on Jurisdiction and Liability, Ad hoc—UNCITRAL Arbitration Rules (2015).
 See Azurix Corp. v. The Argentine Republic, ICSID Case No. ARB/01/12, Award (July 14, 2006); Railroad Development Corporation v. Republic of Guatemala, ICSID Case No. ARB/07/23, Award (June 29, 2012).
 See Saluka Investments B.V. v. The Czech Republic, Partial Award, Ad hoc—UNCITRAL Arbitration Rules (2006); CMS Gas Transmission Company v. The Republic of Argentina, ICSID Case No. ARB/01/8, Award (May 12, 2005).
 See ExxonMobil Investments Canada Inc. and Murphy Oil Corporation v. Canada, ICSID Case No. ARB(AF)/07/4, Award (February 20, 2015).
 Dawson and De Witte (n 18) 1C.
 C-284/16 Slovak Republic v Achmea BV.