Wiki Note: Minimum Standard of Treatment (MST) (2024)

Minimum Standard of Treatment (MST)

I. Definition

The minimum standard of treatment (“MST”) is a rule of customary international law.¹ At least since the beginning of the 20^th century, a large part of doctrine upheld the customary nature of the international minimum standard.² The standard was endorsed by a majority of the States represented at the 1930 Hague Codification Conference.³ The 1962 Declaration on Permanent Sovereignty over Natural Resources also reaffirmed the standard.⁴

Roth, A.H., The Minimum Standard of International Law Applied to Aliens, Leiden, 1949.

Crawford, J., Brownlie’s Principles of Public International Law, Oxford, 8th ed., 2012, pp. 613-614.

Rousseau, C., Droit International Public, 1970, p. 46.

García Amador, F.V., Sohn, L.B. and Baxter, R.R., Recent Codification of the Law of State Responsibility for Injuries to Aliens, Oceana Publications, 1974.

Paparinskis, M., The International Minimum Standard and Fair and Equitable Treatment, Oxford, 2012.

Kurtzn, J., New Aspects of International Investment Law, in Kahn, P. and Wälde, T., Brill / Nijhoff, 2007;Vento Motorcycles, Inc. v. United Mexican States, ICSID Case No. ARB(AF)/17/3, Award, 6 July 2020, para. 282.

As noted by Prof. J. Crawford, this includes the following well-known commentators and scholars: Anzilotti, Verdross, Borchard, Oppenheim, Guggenheim, de Visscher, Scelle, and Jessup. See J. Crawford, Brownlie’s Principles of Public International Law, Oxford, 8^th ed, 2012, p. 613, note 41.

International Law Commission, League of Nations Codification Conference.

U.N. GA Res 1803(XVII), 14 December 1962 (87-2:12).

II. Interpretation of the standard by case law

A. Evolution of the standard

This standard provides a “floor” to the treatment that States must afford to aliens in the form of a set of essential rights that States are obliged to respect vis-à-vis foreign nationals and their property.⁵Tribunals also consider that the standard is “a flexible” standard, which must be adapted to the circ*mstances of each case.⁶

The landmark cases interpreting the standard at the beginning of the 20^th century include: the Neer Claim,⁷Roberts Claim,⁸Hopkins Claim,⁹and British Claims in the Spanish Zone of Morocco.¹⁰More recently, tribunals have discussed the evolution of the standard since the Neer case. Some tribunals held that a broader interpretation may be warranted.¹¹Yet, whether and to what extent the standard has evolved has been debated. Some tribunals have reaffirmed the Neer standard¹² or at least a comparably high threshold, according to which the standardwould be infringed by a conduct that is “arbitrary, grossly unfair, unjust or idiosyncratic, is discriminatory and exposes the claimant to sectional or racial prejudice, or involves a lack of due process leading to an outcome which offends judicial propriety—as might be the case with a manifest failure of natural justice in judicial proceedings or a complete lack of transparency and candour in an administrative process”¹³ or a similar threshold.¹⁴

It has been generally accepted, though, that evidence of bad faith is not necessary, but may be sufficient, to prove a violation of MST.¹⁵And at the very least, bad faith must be considered by arbitral tribunals.¹⁶

Glamis Gold, Ltd. v. United States of America, UNCITRAL, Award, June 8, 2009, para. 615; Grand River Enterprises Six Nations, Ltd., et.al. v. United States of America, Award, January 12, 2011, para. 214 ; Joseph Charles Lemire c. Ukraine (II), ICSID Case No. ARB / 06/18, Decision on Jurisdiction and Liability, January 14, 2010, para. 253; SD Myers, Inc. v. Government of Canada, Partial Award (Merits), 13 November 2000, para. 259;SunReserve Luxco Holdings SRL c. Italy , SCC Case No. 132/2016, Final Award, 25 March 2020, para. 673;OECD (2004), Fair and Equitable Treatment Standard in International Investment Law, OECD Working Papers, 2004/03, OECD Publishing, pp. 8-10.

The Neer Claim, Neer and Neer (U.S.A.) v. United Mexican States, U.S.-Mexico General Claims Commission, Decision, 15 October 1926, para. 4.

Roberts Claim, Roberts (U.S.A.) v. United Mexican States, U.S.-Mexico General Claims Commission, Decision, 2 November 1926, para. 8.

Hopkins Claim, Hopkins (U.S.A.) v. United Mexican States, U.S.-Mexico General Claims Commission, Decision, 31 March 1926, para 16.

British property in Spanish Morocco (Spain v. United Kingdom), Award, 1 May 1925, p. 642.

Glamis Gold, Ltd. v. United States of America, UNCITRAL, Award, 8 June 2009, paras. 614-616; Cargill, Incorporated v. United Mexican States, ICSID Case No. ARB(AF)/05/2, Award, 18 September 2009, para. 286.

B. Interpretation of specific treaty languages

Beyond the debate that has arisen over the existence and implications of the general customary rule, a number of international investment agreements (notably, NAFTA, Bilateral Investment Treaties (“BITs”) based on the successive US Model BITs and recent Free Trade Agreements (“FTAs”) concluded by Canada) include an obligation to accord to protected investors treatment in accordance with international law. Each of these treaty-specific formulations of the MST needs to be considered and interpreted in accordance with its own particular terms.

Most of the cases ruling on the MST so far have applied Article 1105 of the NAFTA treaty, which provides that “treatment in accordance with international law,¹⁷including fair and equitable treatment and full protection and security”¹⁸should be accorded to investors.The debate arose in case law as to the “fair and equitable” element in this provision was¹⁹or was not²⁰ “additive” to the customary international law standard.The NAFTA Parties issued the FTC joint interpretative note clarifying that “[t]he concepts of “fair and equitable treatment” and “full protection and security” do not require treatment in addition to or beyond that which is required by the customary international law minimum standard of treatment of aliens”.²¹The FTC Note was subsequently referred to by tribunals,²² with some tribunals endorsing its interpretation of Article 1105(1)²³ and others finding it unnecessary to decide whether the FTC Note’s interpretation should be followed.²⁴The FTC Note was also referred to by tribunals to affirm that a violation of another obligation under the NAFTA or another treaty does not give rise to a breach of Article 1105.²⁵

Arbitral tribunals constituted under the CAFTA mostly relied on NAFTA case law.²⁶

On the notion of “treatment in accordance with international law” see the following cases:

United Parcel Service of America, Inc. (UPS) v. Government of Canada, ICSID Case No. UNCT/02/1, Award on Jurisdiction, 22 November 2002, para. 98; Merrill & Ring Forestry L.P. v. The Government of Canada, ICSID Case No. UNCT/07/1, Award, 31 March 2010, paras. 184-188; Grand River Enterprises Six Nations, Ltd., et.al. v. United States of America, Award, 12 January 2011, para. 219; Rupert Joseph Binder v. Czech Republic, Final Award, 15 July 2011, paras. 482-485; CME Czech Republic B.V. v. The Czech Republic, Partial Award, 13 September 2001, para. 614; Ulysseas, Inc. v. The Republic of Ecuador, PCA Case No. 2009-19, Final Award, 12 June 2012, para. 245; Electrabel S.A. v. The Republic of Hungary, ICSID Case No. ARB/07/19, Decision on Jurisdiction, Applicable Law and Liability, 30 November 2012, para. 7.158; Rusoro Mining Ltd. v. Bolivarian Republic of Venezuela, ICSID Case No. ARB(AF)/12/5, Award, 22 August 2016, paras. 520-521; Valores Mundiales, S.L. and Consorcio Andino S.L. v. Bolivarian Republic of Venezuela, ICSID Case No. ARB/13/11, Award, 25 July 2017, para. 536;Elliott Associates L.P. v. Republic of Korea, PCA Case No. 2018-51, Award, 20 June 2023, para. 573, 576.

This includes (among others) the cases cited and highlighted above:

Glamis Gold, Ltd. v. United States of America, UNCITRAL, Award, 8 June 2009; Grand River Enterprises Six Nations, Ltd., et.al. v. United States of America, Award, 12 January 2011; S.D. Myers, Inc. v. Government of Canada, Partial Award (Merits), 13 November 2000; Mondev International Ltd. v. United States of America, ICSID Case No. ARB(AF)/99/2, Award, 11 October 2002; ADF Group Inc. v. United States of America, ICSID Case No. ARB(AF)/00/1, Award, 9 January 2003; Waste Management v. United Mexican States (II), ICSID Case No. ARB(AF)/00/3, Award, 30 April 2004; Merrill & Ring Forestry L.P. v. The Government of Canada, ICSID Case No. UNCT/07/1, Award, 31 March 2010; William Ralph Clayton, William Douglas Clayton, Daniel Clayton and Bilcon of Delaware, Inc. v. Government of Canada, PCA Case No. 2009-04, Award on Jurisdiction and Liability, 17 March 2015; International Thunderbird Gaming Corporation v. The United Mexican States, Arbitral Award, 26 January 2006; Loewen Group, Inc. and Raymond L. Loewen v. United States of America, ICSID Case No. ARB(AF)/98/3, Award, 26 June 2003; United Parcel Service of America, Inc. (UPS) v. Government of Canada, ICSID Case No. UNCT/02/1, Award on Jurisdiction, 22 November 2002, para. 80; Windstream Energy LLC v. The Government of Canada, PCA Case No. 2013-22, Award, 27 September 2016, para. 350-352; Crompton (Chemtura) Corp. v. Government of Canada, PCA Case No. 2008-01, Award, 2 August 2010, paras. 122-123; Apotex Holdings Inc. and Apotex Inc. v. United States of America, ICSID Case No. ARB(AF)/12/1, Award, 25 August 2014, paras. 9.15-9.20; Mercer International, Inc. v. Canada, ICSID Case No. ARB(AF)/12/3, Award, 6 March 2018, paras. 7.76-7.78;Elliott Associates L.P. v. Republic of Korea, PCA Case No. 2018-51, Award, 20 June 2023, para. 573.

Pope & Talbot v. Government of Canada, Award on the Merits of Phase 2, 10 April 2001, paras. 110-111, 117-118.

Metalclad Corporation v. The United Mexican States, ICSID Case No. ARB(AF)/97/1, Decision of the Supreme Court of British Columbia on the challenge by the Petitioner 2001 BCSC 664, 02 May 2001, paras. 64-65; Marvin Roy Feldman Karpa v. United Mexican States, ICSID Case No. ARB(AF)/99/1, Award, 16 December 2002, para. 133; Mondev International Ltd. v. United States of America, ICSID Case No. ARB(AF)/99/2, Award, 11 October 2002, para. 122;Elliott Associates L.P. v. Republic of Korea, PCA Case No. 2018-51, Award, 20 June 2023, para. 573.

NAFTA Free Trade Commission, Notes of Interpretation of Certain Chapter 11 Provisions, 31 July 2001.

Tribunals applying other IIAs have also referred to the NAFTA FTC Joint Interpretative Note. SeeGaspar v. Costa Rica.

Pope & Talbot v. Government of Canada, Award in Respect of Damages, 31 May 2002, paras. 23-24; Loewen Group, Inc. and Raymond L. Loewen v. United States of America, ICSID Case No. ARB(AF)/98/3, Award, 26 June 2003, paras. 126, 128; United Parcel Service of America, Inc. (UPS) v. Government of Canada, ICSID Case No. UNCT/02/1, Award on Jurisdiction, 22 November 2002, paras. 94-97; Merrill & Ring Forestry L.P. v. The Government of Canada, ICSID Case No. UNCT/07/1, Award, 31 March 2010, paras. 189, 192-194; Cargill, Incorporated v. United Mexican States, ICSID Case No. ARB(AF)/05/2, Award, 18 September 2009, paras. 267-268; Methanex Corporation v. United States of America, Final Award of the Tribunal on Jurisdiction and Merits, 3 August 2005, para. 21; William Ralph Clayton, William Douglas Clayton, Daniel Clayton and Bilcon of Delaware, Inc. v. Government of Canada, PCA Case No. 2009-04, Award on Jurisdiction and Liability, 17 March 2015, paras. 430-431; Eli Lilly and Company v. Canada, ICSID Case No. UNCT/14/2, Final Award, 16 March 2017, para. 106;Waste Management v. United Mexican States (II), ICSID Case No. ARB(AF)/00/3, Award, 30 April 2004, para. 90;Mobil Investments Canada Inc. and Murphy Oil Corporation v. Government of Canada (I), ICSID Case No. ARB(AF)/07/4, Decision on Liability and Principles of Quantum, 22 May 2012, para. 135;Vento Motorcycles, Inc. v. United Mexican States, ICSID Case No. ARB(AF)/17/3, Award, 6 July 2020, para. 282;Lion Mexico Consolidated L.P. v. United Mexican States, ICSID Case No. ARB(AF)/15/2, Award, 20 September 2021, paras. 208-209; PACC Offshore Services Holdings Ltd v. United Mexican States, ICSID Case No. UNCT/18/5, Award, 11 January 2022, para 254;Alejandro Diego Diaz Gaspar v. Costa Rica, ICSID Case No. ARB/19/13, Award, 29 June 2022, for. 358-361.

Windstream Energy LLC v. Government of Canada, PCA Case No. 2013-22, Award, 27 September 2016, para. 356; Mondev International Ltd. v. United States of America, ICSID Case No. ARB(AF)/99/2, Award, 11 October 2002, paras. 121-122; ADF Group Inc. v. United States of America, ICSID Case No. ARB(AF)/00/1, Award, 9 January 2003, paras. 176-178; International Thunderbird Gaming Corporation v. The United Mexican States, Arbitral Award, 26 January 2006, paras. 192-193; Glamis Gold Ltd. v. United States of America, Award, 8 June 2009, para. 599; Crompton (Chemtura) Corp. v. Government of Canada, PCA Case No. 2008-01, Award, 2 August 2010, paras. 119-120; Grand River Enterprises Six Nations, Ltd., et.al. v. United States of America, Award, 12 January 2011, paras. 175-176, 181; Loewen Group, Inc. and Raymond L. Loewen v. United States of America, ICSID Case No. ARB(AF)/98/3, Award, 26 June 2003, paras. 125-126; Eli Lilly and Company v. Canada, ICSID Case No. UNCT/14/2, Government of Canada Statement of Defence, para. 222;Lion Mexico Consolidated L.P. v. United Mexican States, ICSID Case No. ARB(AF)/15/2, Award, 20 September 2021, paras. 208-209.

GAMI Investments, Inc. v. United Mexican States, Final Award, 15 November 2004, para. 92; Methanex Corporation v. United States of America, Partial Award, 7 August 2002, para. 102; United Parcel Service of America, Inc. (UPS) v. Government of Canada, ICSID Case No. UNCT/02/1, Award on Jurisdiction, 22 November 2002, para. 97.

Cargill, Incorporated v. United Mexican States, ICSID Case No. ARB(AF)/05/2, Award, 18 September 2009, para. 295; Grand River Enterprises Six Nations, Ltd., et.al. v. United States of America, Award, 12 January 2011, para. 71.

Railroad Development Corporation (RDC) v. Republic of Guatemala, ICSID Case No. ARB/07/23, Award, 29 June 2012, paras. 216-219; Aaron C. Berkowitz, Brett E. Berkowitz and Trevor B. Berkowitz v. Republic of Costa Rica, ICSID Case No. UNCT/13/2, Interim Award (Corrected), 30 May 2017, paras. 282-283; David R. Aven, Samuel D. Aven, Carolyn J. Park, Eric A. Park, Jeffrey S. Shioleno, Giacomo A. Buscemi, David A. Janney and Roger Raguso v. The Republic of Costa Rica, ICSID Case No. UNCT/15/3, Final Award, 18 September 2018, para. 297; The Lopez-Goyne Family Trust and others v. Republic of Nicaragua, ICSID Case No. ARB/17/44, Award, 1 March 2023, paras. 411,415.

III. Scope of MST under customary international law

Some tribunals have considered whether the claimant should prove the existence of or a change in a rule of customary international law breached by the State.²⁷

The customary MST has been generally understood to comprise rights, guarantees and obligations:

with respect to the administration of justice in cases involving aliens (which evolved in the standard of denial of justice now also embodied under the Fair and equitable treatmentformulations of most BITs);²⁸
concerning the protection of aliens and their property from specific disturbances caused within the State’s territory;²⁹
regarding the treatment of aliens under detention in accordance with an “ordinary standard of civilization”;³⁰and
in case of expulsion of aliens;³¹
of transparency, with some tribunalshaving an opposite view;³² and
of due process.³³

10.

Tribunals also considered that “something more than simple illegality or lack of authority under the domestic law of a State” is necessary for a breach of the MST to be constituted.³⁴

11.

However, tribunals do not have “an open-ended mandate to second guess government decision-making”³⁵or to pass judgment on the State’s policy rationale for the measure.³⁶Similarly, not all failures to satisfy the requirements of national law or to fulfil the objectives of administrative regulations rise to the level of a violation of international law.³⁷

12.

Violation of these rights would give rise to the State’s international responsibility under international law, which, in most cases, may lead to diplomatic protection by the alien’s state of nationality, on the alien’s behalf, and generally subject to the exhaustion of local remedies rule.³⁸The MST is not contingent upon the State’s domestic legislation or practices.³⁹

Janes Claim in U.S.A. (Laura M.B. Janes et al) v. United Mexican States (1925), U.S.-Mexico General Claims Commission, Decision, 16 November 1925, para. 22;Bridgestone Americas, Inc. and Bridgestone Licensing Services, Inc. v. Republic of Panama, ICSID Case No. ARB/16/34, Award, 14 August 2020, para. 178;Lion Mexico Consolidated L.P. v. United Mexican States, ICSID Case No. ARB(AF)/15/2, Award, 20 September 2021, para. 210;Elliott Associates L.P. v. Republic of Korea, PCA Case No. 2018-51, Award, 20 June 2023, para. 569.

OECD (2004), Fair and Equitable Treatment Standard in International Investment Law, OECD Working Papers, 2004/03, OECD Publishing, note 43.

Roberts Claim, Roberts (U.S.A.) v. United Mexican States, U.S.-Mexico General Claims Commission, Decision, 2 November 1926, para. 8;Interocean Oil Development Company and Interocean Oil Exploration Company v. Federal Republic of Nigeria, ICSID Case No. ARB/13/20, Award, 6 October 2020, paras. 355-356.

Boffolo case, Italian-Venezuela Commission, Opinion of Ralston, umpire, 1 January 1903, pp. 531-534.

Crawford, J., State Responsibility: The General Part, Cambridge, 2013, pp. 580-584 (Chapter 18 - Claims on behalf of others: diplomatic and functional protection).

International Law Commission (ILC) Articles on Diplomatic Protection, ILC Report 2006, UN Doc. A/61/10, Articles 14-15.

OECD (2004), Fair and Equitable Treatment Standard in International Investment Law, OECD Working Papers, 2004/03, OECD Publishing, note 32.

ADF Group Inc. v. United States of America, ICSID Case No. ARB(AF)/00/1, Award, 9 January 2003, paras. 182-186; United Parcel Service of America, Inc. (UPS) v. Government of Canada, ICSID Case No. UNCT/02/1, Award on Jurisdiction, 22 November 2002, paras. 83-84, 92, 95-97; Glamis Gold Ltd. v. United States of America, Award, 8 June 2009, paras. 601-605, 626;Methanex Corporation v. United States of America, UNCITRAL, Final Award, 3 August 2005, Part IV, Chapter C, para. 26;Cargill, Incorporated v. United Mexican States, ICSID Case No. ARB(AF)/05/2, Award, 18 September 2009, paras. 273;Windstream Energy LLC v. Government of Canada, PCA Case No. 2013-22, Award, 27 September 2016, para. 350.

Metalclad Corporation v. The United Mexican States, ICSID Case No. ARB(AF)/97/1, Award, 30 August 2000, paras. 70, 76, 88, 99; Metalclad Corporation v. The United Mexican States, ICSID Case No. ARB(AF)/97/1, Decision of the Supreme Court of British Columbia on the challenge by the Petitioner 2001 BCSC 664, 2 May 2001, paras. 70-72; S.D. Myers, Inc. v. Government of Canada, Separate Opinion by Dr. Bryan Schwartz concurring except with respect to performance requirements, in the partial award of the tribunal, paras. 250-258; Marvin Roy Feldman Karpa v. United Mexican States, ICSID Case No. ARB(AF)/99/1, Award, 16 December 2002, para. 133; International Thunderbird Gaming Corporation v. The United Mexican States, Separate Opinion of Mr. Thomas Wälde (Arbitral Award), paras. 11, 36-37; Waste Management v. United Mexican States (II), ICSID Case No. ARB(AF)/00/3, Award, 30 April 2004, para. 98; Cargill, Incorporated v. United Mexican States, ICSID Case No. ARB(AF)/05/2, Award, 18 September 2009, paras. 285, 294; Merrill & Ring Forestry L.P. v. The Government of Canada, ICSID Case No. UNCT/07/1, Award, 31 March 2010, paras. 208, 231; Mercer International, Inc. v. Canada, ICSID Case No. ARB(AF)/12/3, Award, 6 March 2018, para. 7.77;Windstream Energy LLC v. The Government of Canada, PCA Case No. 2013-22, Award, 27 September 2016, paras. 379-380;The Lopez-Goyne Family Trust and others v. Republic of Nicaragua, ICSID Case No. ARB/17/44, Award, 1 March 2023, paras. 426-427.

Mondev International Ltd. v. United States of America, ICSID Case No. ARB(AF)/99/2, Award, 11 October 2002, para. 127; Loewen Group, Inc. and Raymond L. Loewen v. United States of America, ICSID Case No. ARB(AF)/98/3, Award, 26 June 2003, paras. 131-132; Waste Management v. United Mexican States (II), ICSID Case No. ARB(AF)/00/3, Award, 30 April 2004, para. 98; International Thunderbird Gaming Corporation v. The United Mexican States, Arbitral Award, 26 January 2006, paras. 197-201; Crompton (Chemtura) Corp. v. Government of Canada, PCA Case No. 2008-01, Award, 02 August 2010, paras. 145-147, 162; Apotex Holdings Inc. and Apotex Inc. v. United States of America, ICSID Case No. ARB(AF)/12/1, Award, 25 August 2014, paras. 9.27, 9.43, 9.47-9.49; William Ralph Clayton, William Douglas Clayton, Daniel Clayton and Bilcon of Delaware, Inc. v. Government of Canada, PCA Case No. 2009-04, Award on Jurisdiction and Liability, 17 March 2015, paras. 543, 588-594; Jorge Luis Blanco, Joshua Dean Nelson and Tele Fácil México, S.A. de C.V. v. United Mexican States, ICSID Case No. UNCT/17/1, Final Award, 05 June 2020, paras. 358-359; TECO Guatemala Holdings, LLC v. Republic of Guatemala, ICSID Case No. ARB/10/23, Award, 19 December 2013, paras. 457-458; David R. Aven, Samuel D. Aven, Carolyn J. Park, Eric A. Park, Jeffrey S. Shioleno, Giacomo A. Buscemi, David A. Janney and Roger Raguso v. The Republic of Costa Rica, ICSID Case No. UNCT/15/3, Final Award, 18 September 2018, para. 413; Quiborax S.A., Non-Metallic Minerals S.A. v. Plurinational State of Bolivia, ICSID Case No. ARB/06/2, Award, 16 September 2015, para. 221;Vento Motorcycles, Inc. v. United Mexican States, ICSID Case No. ARB(AF)/17/3, Award, 6 July 2020, para. 284; Antonio del Valle Ruiz et al. v. Kingdom of Spain, PCA Case No. 2019-17, Final Award, 13 March 2023, para. 519.

Cargill, Incorporated v. United Mexican States, ICSID Case No. ARB(AF)/05/2, Award, 18 September 2009, para. 293; Merrill & Ring Forestry L.P. v. The Government of Canada, ICSID Case No. UNCT/07/1, Award, 31 March 2010, para. 219; Glamis Gold Ltd. v. United States of America, Award, 8 June 2009, paras. 625-626; GAMI Investments, Inc. v. United Mexican States, Final Award, 15 November 2004, para. 98; ADF Group Inc. v. United States of America, ICSID Case No. ARB(AF)/00/1, Award, 9 January 2003, para. 190;Gramercy Funds Management LLC, and Gramercy Peru Holdings LLC v. The Republic of Peru, ICSID Case No. UNCT/18/2, Final Award, 6 December 2022, para. 968

S.D. Myers, Inc. v. Government of Canada, Partial Award (Merits), 13 November 2000, paras. 261; S.D. Myers, Inc. v. Government of Canada, Separate Opinion by Dr. Bryan Schwartz concurring except with respect to performance requirements, in the partial award of the tribunal, para. 230; GAMI Investments, Inc. v. United Mexican States, Final Award, 15 November 2004, para. 93; Cargill, Incorporated v. United Mexican States, ICSID Case No. ARB(AF)/05/2, Award, 18 September 2009, para. 292; Crompton (Chemtura) Corp. v. Government of Canada, PCA Case No. 2008-01, Award, 02 August 2010, para. 134; Mobil Investments Canada Inc. and Murphy Oil Corporation v. Government of Canada (I), ICSID Case No. ARB(AF)/07/4, Decision on Liability and Principles of Quantum, 22 May 2012, para. 153.

Cargill, Incorporated v. United Mexican States, ICSID Case No. ARB(AF)/05/2, Award, 18 September 2009, para. 296; Merrill & Ring Forestry L.P. v. The Government of Canada, ICSID Case No. UNCT/07/1, Award, 31 March 2010, para. 236; Crompton (Chemtura) Corp. v. Government of Canada, PCA Case No. 2008-01, Award, 02 August 2010, paras. 134, 153-154;Antonio del Valle Ruiz et al. v. Kingdom of Spain, PCA Case No. 2019-17, Final Award, 13 March 2023, paras. 520-522.

Cargill, Incorporated v. United Mexican States, ICSID Case No. ARB(AF)/05/2, Award, 18 September 2009, para. 287; GAMI Investments, Inc. v. United Mexican States, Final Award, 15 November 2004, para. 97; Marvin Roy Feldman Karpa v. United Mexican States, ICSID Case No. ARB(AF)/99/1, Award, 16 December 2002, para. 78.

IV. Relationship with the fair and equitable treatment standard

13.

It remains a matter of debate whether the Fair and equitable treatment standard currently reflects the MST or offers an autonomous standard that is additional to general international law.⁴⁰ A number of investment tribunals suggest that the difference between FET and MST may well be "more apparent than real, when applied to the specific facts of a case."⁴¹

Dolzer, R. and Schreuer, C., Principles of International Investment Law, Oxford, 2012, pp. 134-139:

"there are growing doubts about the relevance of this whole debate. […] The emphasis on linkages between FET and customary international law is unlikely to restrain the evolution of the FET standard. […]"

Spółdzielnia Pracy Muszynianka v. Slovak Republic, PCA Case No. 2017-08, Award, 7 October 2020, para. 459;Cairn Energy PLC and Cairn UK Holdings Limited v. The Republic of India, PCA Case No. 2016-07, Final Award, 21 December 2020, paras. 1701-1704; GPF GP S.à.r.l v. Poland, SCC Case No. 2014/168, Final Award, 29 April 2020, para. 538;Infinito Gold Ltd. v. Republic of Costa Rica, ICSID Case No. ARB/14/5, Award, 3 June 2021, paras. 340-350;Global Telecom Holding S.A.E. v. Canada, ICSID Case No. ARB/16/16, Award, 27 March 2020, paras. 484-486; SunReserve Luxco Holdings SRL v. Italy, SCC Case No. 132/2016, Final Award, 25 March 2020, paras. 672-673; Mohamed Abdel Raouf Bahgat v. Arab Republic of Egypt, PCA Case No. 2012-07, Final Award, 23 December 2019, para. 247; Belenergia S.A. v. Italian Republic, ICSID Case No. ARB/15/40, Award, 6 August 2019, para. 568;Air Canada v. Bolivarian Republic of Venezuela, ICSID Case No. ARB(AF)/17/1, Award, 13 September 2021, paras. 446-447;Gramercy Funds Management LLC, and Gramercy Peru Holdings LLC v. The Republic of Peru, ICSID Case No. UNCT/18/2, Final Award, 6 December 2022, paras. 823-825;Antonio del Valle Ruiz et al. v. Kingdom of Spain, PCA Case No. 2019-17, Final Award, 13 March 2023, para. 513; Public Joint Stock Company Mobile TeleSystems v. Turkmenistan (II), ICSID Case No. ARB(AF)/18/4, Award, 14 June 2023, para. 373;Peteris Pildegovics and SIA North Star v. Kingdom of Norway, ICSID Case No. ARB/20/11, Award, 22 December 2023, para. 498;Red Eagle Exploration Limited v. Republic of Colombia, ICSID Case No. ARB/18/12, Award, 28 February 2024, para. 287.

Saluka v. Czech Republic, PCA Case No. 2001-04, Partial Award, 17 March 2006, para. 291; Azurix v. Argentina, ICSID Case No. ARB/01/12, Award, 14 July 2006, paras. 361, 364; Duke Energy v. Ecuador, ICSID Case No. ARB/04/19, Award, 18 August 2008, paras. 332-337; Impregilo v. Argentina, ICSID Case No. ARB/07/17, Award, 21 June 2011, paras. 287-289; El Paso v. Argentina, ICSID Case No. ARB/03/15, Award, 31 October 2011, para. 335;Thomas Gosling and others v. Republic of Mauritius, ICSID Case No. ARB/16/32, Award, 18 February 2020, para. 243;Anglo American PLC v. Bolivarian Republic of Venezuela, ICSID Case No. ARB(AF)/14/1, Award, 18 January 2019, paras. 438-439.

V. Relationship with the full protection and security standard

14.

Similarly, there remains debate on whether the Full protection and security standardis autonomous from the minimum standard of treatment or if it simply mirrors it.⁴² Some tribunals have confined the full protection and security standard to the customary minimum standard of treatment,⁴³ particularly when the treaty’s provisions expressly refer to general international law.⁴⁴ Other tribunals have distinguished the two, either by recognizing that they are two distinct standards,⁴⁵or by defining the minimum standard of treatment as the minimum standard to which the full protection and security standard must a least conform, but beyond which it can extend.⁴⁶

Junngam, N., The Full Protection and Security Standard in International Investment Law: What and Who is Investment Fully [?] Protected and Secured From?, American University Business Law Review, Vol. 7, No. 1, 2018, p. 48; Noble Ventures, Inc. v. Romania, ICSID Case No. ARB/01/11, Award, 12 October 2005, para. 164.

El Paso Energy International Company v. Argentine Republic, ICSID Case No. ARB/03/15, Award, 31 October 2011, para. 522; Oxus Gold plc v. Republic of Uzbekistan, the State Committee of Uzbekistan for Geology & Mineral Resources, and Navoi Mining & Metallurgical Kombinat, Final Award, 17 December 2015, para. 353.

In this vein, see also paragraph 6 above on tribunals interpreting the provisions of the NAFTA.

Adel A Hamadi Al Tamimi v. Sultanate of Oman, ICSID Case No. ARB/11/33, Award, 3 November 2015, para. 380; Railroad Development Corporation (RDC) v. Republic of Guatemala, ICSID Case No. ARB/07/23, Award, 29 June 2012, para. 238.

Crystallex International Corporation v. Bolivarian Republic of Venezuela, ICSID Case No. ARB(AF)/11/2, Award, 4 April 2016, para. 632.

Elettronica Sicula S.p.A. (ELSI) (United States of America v. Italy), Judgment, 20 July 1989, para. 111; American Manufacturing & Trading, Inc. v. Republic of Zaire, ICSID Case No. ARB/93/1, Award, 21 February 1997, para. 6.06; Asian Agricultural Products Ltd. (AAPL) v. Republic of Sri Lanka, ICSID Case No. ARB/87/3, Award, 27 June 1990, para. 50; Azurix Corp. v. The Argentine Republic (I), ICSID Case No. ARB/01/12, Award, 14 July 2006, para. 361.

VI. MST in investment treaty practice – specific formulations of MST

15.

The most salient formulations of MST in current treaty practice are found in NAFTA (Article 1105), the US Model BIT (Article 5), and several FTAs recently concluded by Canada (e.g., CPTPP or the Canada-Colombia FTA).⁴⁷These treaty formulations clarify that:

the MST provision prescribed the customary rule as a minimum standard of treatment;
references to the Fair and equitable treatmentand Full protection and securitystandards do not require treatment “in addition to or beyond” that required under MST; and
a determination of a breach of any other standard of protection does not per se establish a breach of the MST. Such reference does not create additional substantive rights.

NAFTA (1992), Article 1105; Official interpretation by the NAFTA Free Trade Commission, FTC Note of Interpretation of 31 July 2001; US Model BIT (2012), Art. 5 and Annex A; Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) (2018), Art. 9.6, Annex 9-A; Canada-Colombia FTA (2008), Art. 805;Eco Oro Minerals Corp. v. Republic of Colombia, ICSID Case No. ARB/16/41, Decision on Jurisdiction, Liability and Directions on Quantum, 9 September 2021, paras. 743-747.

VII. Possibility to elevate the MST standard of protection by recourse to MFN treatment

16.

The possibility to elevate the protection offered by MST by importing - through Most favored nation provisions - other standards of substantive protection still remains a matter unaddressed in international investment jurisprudence despite having been proposed by a number of claimant investors.⁴⁸

ADF Group Inc. v. United States of America, ICSID Case No. ARB(AF)/00/1, Award, 9 January 2003, para. 199; Italba Corporation v. Oriental Republic of Uruguay, ICSID Case No. ARB/16/9, Award, 22 March 2019, paras. 124, 126; Italba Corporation v. Oriental Republic of Uruguay, ICSID Case No. ARB/16/9, Claimants’ Memorial, 16 September 2016, paras. 168-171; Italba Corporation v. Oriental Republic of Uruguay, ICSID Case No. ARB/16/9, Uruguay’s Counter Memorial, 30 January 2017, paras. 199-203; Italba Corporation v. Oriental Republic of Uruguay, ICSID Case No. ARB/16/9, Uruguay’s Rejoinder, 11 August 2017, para. 304.