¹ See for all, Art. 66(3) of the 1998 Rome Statute of the International Criminal Court, 2187 UNTS 3.

² Art. 21(3) of the Understanding on Rules and Procedures Governing the Settlement of Disputes (Annex 2 of the 1994 WTO Agreements, 33 ILM 1226); see also, Art. 21 of the Statute of the Court of Justice of the European Union (Protocol No 3 to the Treaty on European Union and the Treaty on the Functioning of the European Union (1992) OJ 212/C 326/1) and Art. 41(1) of the Permanent Court of Arbitration Rules 2012, available at www.pca-cpa.org/wp-content/uploads/sites/175/2015/11/PCA-Arbitration-Rules-2012.pdf.

³ See Arts. 6(3), 5(1) and 5(3), 1950 European Convention for the Protection of Human Rights and Fundamental Freedoms, 213 UNTS 222; Art. 9(3), 1966 International Covenant on Civil and Political Rights, 999 UNTS 171; Arts. 7(1)(d), 7(5) and 8(1), 1969 American Convention on Human Rights, 1144 UNTS 123.

⁴ EC Measures Concerning Meat and Meat Products (EC-Hormones), WT/DS26/AB/R, WT/DS48/AB/R, Appellate Body Reports of 16 January 1998, para. 590.

⁵ See, for instance, Armed Activities in the Territory of the Congo (Democratic Republic of the Congo v. Uganda), Order of 29 November 2001, [2001] ICJ Rep. 660, at 681, paras. 48–9 (deadline for submitting counter-claims) and Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States), Judgment of 26 November 1984, [1984] ICJ Rep. 292, at 420, para. 62 (withdrawal of an optional clause declaration).

⁶ See, for instance, Reparations for Injuries Suffered in the Service of the United Nations, Advisory Opinion of 11 April 1949, [1949] ICJ Rep. 174, at 181, and Ahmadou Sadio Diallo (Republic of Guinea v. Democratic Republic of the Congo), Compensation, Judgment of 19 June 2012, [2012] ICJ Rep. 324, at 335, para. 24. Regarding treaty interpretation and maritime delimitation, further references will be provided in subsequent sections.

⁷ Elettronica Sicula S.P.A. (ELSI) (United States of America v. Italy), Merits, Judgment of 20 July 1989, [1989] ICJ Rep. 15, at 74, para. 124.

⁸ The exceptions are the well-known works of O. Corten, L'utilisation du ‘raisonnable’ par le juge international, Discours juridique, raison et contradictions (1997), and J. Salmon, ‘Le concept du “raisonnable” en droit international public’, in Mélanges Reuter (1982), 447–78. See also E. Cannizaro, Il principio della proporzionalità nell'ordinamento internazionale (2000), 166–202.

⁹ Whaling in the Antarctic (Australia v. Japan: New Zealand intervening), Merits, Judgment of 31 March 2014, [2014] ICJ Rep. 226.

¹⁰ Ibid., at 316, para. 39 (Judge Owada, Dissenting Opinion).

¹¹ Ibid.

¹² Ibid., at 328, para. 28 (Judge Abraham, Dissenting Opinion).

¹³ Ibid., at 386–8, paras. 12–17 (Judge Yusuf, Dissenting Opinion).

¹⁴ S.R. Tully, ‘“Objective Reasonableness” as a Standard for International Judicial Review’, (2015) 6 JIDS 546. For a more nuanced approach, see G. Gros, ‘The ICJ's Handling of Science in the Whaling in the Antarctic Case: A Whale of a Case?’, (2015) 6 JIDS 578.

¹⁵ See, for instance, C. Foster, ‘Motivations and Methodologies: Was Japan's Whaling Programme for Purposes of Scientific Research?’ (2014), at 14, available at www.edu.kobe-u.ac.jp/ilaw/en/whaling_docs/paper_Foster.pdf; Ioannidis, M., ‘Beyond the Standard of Review: Deference Criteria in WTO Law and the Case for a Procedural Approach’, in Gruszczynski, L. and Werner, W. (eds.), Deference in International Courts and Tribunals (2014), 95 Google Scholar.

¹⁶ See in particular Mare, W. de la, Gales, N. and Mangel, M., ‘Applying Scientific Principles in International Law on Whaling’, (2014) 345 Science 1125–6CrossRefGoogle ScholarPubMed; see also E. Cannizaro, ‘Margin of Appreciation and Reasonableness in the ICJ's Decision in the Whaling Case’, in Les limites du droit international: essaies en l'honneur de Joe Verhoeven - The Limits of International Law: Essays in Honour of Joe Verhoeven (2015), 449; Kolb, R., ‘Short Reflections on the ICJ's Whaling Case and the Review by International Courts and Tribunals of “Discretionary Powers”’, (2015) 32 Australian Yearbook of International Law 135 Google Scholar; J. Wyatt, ‘Should We Presume that Japan Acted in Good Faith? Reflections on Judge Abraham's Burden of Proof Based Analysis’, ibid., at 145.

¹⁷ M. Bennouna, ‘La Cour internationale de Justice et les droits de l'homme’, conference delivered at the University of Salamanca in commemoration of the 70^th Anniversary of the UN Charter, 8 April 2015, on file with the author.

¹⁸ While the title of this article uses the ICJ's terminology, I will use ‘reasonableness’ and ‘objective reasonableness’ interchangeably. I will elaborate on this point in infra note 98.

¹⁹ For a systematic analysis of the problem of uncertainty in international law, J. Kammerhofer, Uncertainty in International Law, A Kelsenian Perspective (2011).

²⁰ On notions of ‘variable geometry’ or ‘variable content’ in law, see C. Perelmann and R.V. Elst, Les notions à contenu variable en droit (1984).

²¹ I understand ‘judicial adjudication’ as the task of ‘spécifier et . . . fixer la teneur de la règle et les conséquences juridiques qui en découlent par rapport à une situation donnée de manière définitive, pour les besoins de la sécurité juridique’ (the task of ‘defining the content of legal rules and establishing the consequences derived from non-compliance with them in a particular situation; see G. Abi-Saab, ‘Cours général de droit international public’, (1987) 207 RCADI 9, at 214) (my own translation).

²² Besson, S., ‘Legal Philosophical Issues of International Adjudication’, in Romano, P.R., Alter, K. and Shany, Y. (eds.), The Oxford Handbook of International Adjudication (2013), 413 Google Scholar at 420; G.I. Hernández, The International Court of Justice and the Judicial Function (2014), 101; Y. Shany, ‘Toward a General Margin of Appreciation Doctrine in International Law’ (2006) 16(5) EJIL 907, at 912–13.

²³ A. Von Bogdandy and I. Venzke, ‘In Whose Name? An Investigation of International Courts’ Public Authority and Its Democratic Justification’, (2013) 23(1) EJIL 7, at 15.

²⁴ Cahin, G., ‘La motivation des décisions des juridictions internationales’, in Ruiz-Fabri, H. and Sorel, J.-M. (eds.), La motivation des décisions des juridictions internationales (2008), 9 Google Scholar at 10–14.

²⁵ T.M. Franck, ‘Fairness in the International Legal and Institutional System: General Course on Public International Law’, (1993) 240(III) RCADI 9, at 303.

²⁶ This is what Besson labels the ‘interpretive authority’ of judicial decisions (see Besson, supra note 22, at 420. See also Cahin, supra note 24, at 50–1).

²⁷ For the purposes of this article, I will establish a formal distinction between interpretation and application of a treaty, although the difference between both notions is relative (see on this point Hernández, G.I., ‘Interpretative Authority and the International Judiciary’, in Bianchi, A., Peat, D. and Windsor, M. (eds.), Interpretation in International Law (2015), 166 CrossRefGoogle Scholar at 175–81. Contra, J. Kommerhafer, Uncertainty in International Law: A Kelsenian Perspective (2011), 124).

On another issue, the above finding applies also to scientific disputes. See A. Orford, ‘Scientific Reason and the Discipline of International Law’, (2014) 25(2) EJIL 369, at 382. More specifically, with regard to whaling, see M. Fitzmaurice, Whaling and International Law (2015), 57 and 87.

²⁸ P. Martens, ‘L'irrésistible ascension du principe de proportionnalité’, in Présence du droit public et des droits de l'homme: Mélanges offerts à Jacques Velu (1992), 49 at 60–1; Bogdandy and Venzke, supra note 23, at 14.

²⁹ See Besson, supra note 22, at 420–33. See also M. Koskenniemi, From Apology to Utopia: The Structure of International Legal Argument (2005), 63.

³⁰ See, for instance, J.E. Álvarez, ‘What are International Judges for? The Main Functions of Judicial Adjudication’, in Romano, Alter and Shany (eds.), supra note 22, at 167 and 169–70; and Shany, supra note 22, at 911.

³¹ See Corten, supra note 8, at 368.

³² See Hernández, supra note 22, at 100–101.

³³ ‘Thus, fifteen different judges having a different experience and different philosophies, have yet something in common: the converging universality of modern international law and of its way of thinking’ (my own translation) ( Bedjaoui, M.: ‘La fabrication des décisions de la Cour internationale de Justice’, in Bedjaoui, M. et al. (eds.), La méthode de travail du juge international: Actes de la journée d’études du 23 novembre 1996 (1997), 55 Google Scholar at 65). See also Corten, supra note 8, at 368 and 423.

³⁴ See for all Craig, P., ‘The Nature of Reasonableness Review’, (2013) 66 (1) Current Legal Problems 131 CrossRefGoogle Scholar.

³⁵ I am nevertheless aware of the fact that the term ‘reason’ may not find easy accommodation in some non-Western legal cultures. In the case of China, see for instance M. Delmas-Marty, Ordering Pluralism: A Conceptual Framework for Understanding the Transnational Legal World (2009), 5 (with an example concerning Art. 1 of the 1948 Universal Declaration of Human Rights).

³⁶ G. Luchetti and A. Petrucci, Fondamenti romanistici del diritto europeo: Le obbligazioni et i contratti dalle radici romane al Draft Common Frame of Reference (2010), 55–62.

³⁷ R. Kolb, Théorie du droit international (2013), 785.

³⁸ Luchetti and Petrucci, supra note 36, at 55–62. See also the Draft Common Frame of Reference (an authoritative scholarly work aimed at systematizing the main principles, definitions and rules of European Contract Law), which defines ‘reasonableness’ both as a general principle of contract law and as a parameter of assessment of good faith behaviour ( Bar, C. Von et al. (eds.), Principles, Definitions and Model Rules of European Private Law, Draft Common Frame of Reference (2009), 178 Google Scholar).

³⁹ See Cannizaro, supra note 8, at 21. The author describes ‘reasonableness’ as having a ‘lower technical character’ (‘minore caratterizzazione tecnica’).

⁴⁰ H. Lauterpacht, The Function of Law in the International Community (1933), 110–35.

⁴¹ See, in particular, Continental Shelf (Libya v. Malta), Judgment of 3 June 1985, [1985] ICJ Rep. 3, at 53–5, para. 75; Territorial and Maritime Dispute between Nicaragua and Honduras in the Caribbean Sea (Nicaragua v. Honduras), Merits, Judgment of 8 October 2007, [2007] ICJ Rep. 659, at 742, para. 277; Maritime Delimitation in the Black Sea (Romaine v. Ukraine), Merits, Judgment of 3 February 2009, [2009] ICJ Rep. 61, at 88, para. 75.

⁴² See, for instance, the assessment by the European Court of Human Rights of the ‘strict proportionality’ of a detention measure following declaration of a state of emergency under Art. 15 of the European Convention on Human Rights (A. and others v. United Kingdom (3455/05, para. 182)).

⁴³ See Craig, supra note 34, at 37. I will not deal here with factual uncertainty, in relation to which ‘reasonableness’ may also be pertinent, as the ICJ's case law shows (Corfu Channel case (United Kingdom of Great Britain and Northern Ireland v. Albania), Merits, Judgment of 9 April 1949, [1949] ICJ Rep. 4, at 18; Application of the Convention on the Prevention and the Punishment of the Crime of Genocide (Croatia v. Serbia), Merits, Judgment of 3 February 2015, para. 147; and Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), Merits, Judgment of 27 July 1986, [1986] ICJ Rep. 14, at 83, para. 153).

⁴⁴ Kammerhofer, supra note 19, at 124. See also Koskenniemi, supra note 29, at 61–2.

⁴⁵ H. Kelsen, Pure Theory of Law (1970), 352. See also Abi-Saab, supra note 21, at 215.

⁴⁶ Abi-Saab, supra note 21, at 33 (my own translation).

⁴⁷ O. Schachter, ‘International Law in Theory and in Practice: General Course on Public International Law’ (1982) 178(V) RCADI 9, at 85. See Aristotle, Nicomachean Ethics (Trad. 1999), 89: ‘When the law speaks universally, then, a case arises on it which is not covered by the universal statement, then it is right, where the legislator fails us and has erred by oversimplicity, to correct the omission – to say what the legislator himself would have said had he been present, and would have put into his law if he had known.’

⁴⁸ See Gabčíkovo-Nagymaros Project (Hungary v. Slovakia), Merits, Judgment of 25 September 1997, [1997] ICJ. Rep. 7, at 53, para. 75; and Art. 5 of the 1997 Convention on the Law of the Non-navigational Uses of International Watercourses, no UNTS yet determined, available at www.treaties.un.org/Pages/UNTSOnline.aspx?id=1.

⁴⁹ Pulp Mills on the Uruguay River (Argentina v. Uruguay), Judgment of 20 April 2010, [2010] ICJ Rep. 14, at 74–5, para. 177.

⁵⁰ Delimitation of the Maritime Boundary in the Gulf of Maine Area (Canada v. United States of America), Merits, Judgment of 12 October 1984, [1984] ICJ Rep. 246, at 313, para. 58, emphasis added. This is notwithstanding the fact that, in Continental Shelf (Libya v. Malta), the Court re-oriented this extreme conception of the principle towards a more objectivistic approach, as a consequence of which equitable criteria became more general and predictable (Continental Shelf (Libya v. Malta), Merits, Judgment of 3 June 1985, [1985] ICJ Rep. 13, at 38–40, paras. 40–5.

⁵¹ South West Africa (Liberia v. South Africa), Second Phase, Judgment of 18 July 1966, [1966] ICJ Rep. 6, at 34, para. 49 (emphasis added).

⁵² Abi-Saab, supra note 21, at 33 (my own translation).

⁵³ See Gabčíkovo-Nagymaros Project case, supra note 48, at 78–9, para. 142. Certainly, this statement was made with regard to the particular circumstances of the case. Thus, after years of non-compliance by the Parties with various provisions of the 1977 Treaty concerning the construction and operation of the Gabčíkovo-Nagymaros System of Locks and the progressive development of international environmental law, the Court had to focus on the object and purpose of the treaty instead of relying on a literal interpretation of that Treaty (see below 3.1).

⁵⁴ This is famously the case of the ICRW, which, as is known, is based on a difficult tension between sustainable whaling and the conservation of whale populations (M. Fitzmaurice, Whaling and International Law (2015), 67). See more generally N. MacCormick, Rethoric and the Rule of Law (2005), 180–1.

⁵⁵ MacCormick, supra note 54, at 186.

⁵⁶ On judicial adjudication as an act of will, see Kelsen, supra note 45, at 353–5; Kammerhofer, supra note 19, at 109–11; Hernández, supra note 27, at 169.

⁵⁷ See Corten, supra note 8, at 378. For an enlightening attempt to systematize the Court's standards of review, see Mar, K. del, ‘The International Court of Justice and Standards of Proof’, in Bannelier, K., Christakis, T. and Heathcote, S. (eds.), The ICJ and the Evolution of International Law (2012), 98–123 Google Scholar.

⁵⁸ According to this provision, ‘[t]he function of panels is to assist the DSB in discharging its responsibilities under this Understanding and the covered agreements. Accordingly, a panel should make an objective assessment of the matter before it, including an objective assessment of the facts of the case and the applicability of and conformity with the relevant covered agreements . . .’ (Art. 11 of the Understanding on rules and procedures governing the settlement of disputes). As to human rights courts, see infra note 77.

⁵⁹ 1946 International Convention for the Regulation of Whaling, 161 UNTS 364.

⁶⁰ CR 2013/19, at 65, para. 22 (Crawford).

⁶¹ CR 2013/22, at 60, para. 21 (Lowe).

⁶² Whaling in the Antarctic case, supra note 9, at 253, para. 61.

⁶³ Ibid., at 254, para. 67.

⁶⁴ Ibid., at 268–71, paras. 128–44.

⁶⁵ Ibid., at 272–90, paras. 145–212

⁶⁶ Ibid., at 290–2, paras. 213–22.

⁶⁷ Ibid., at 292–4, paras. 224–7.

⁶⁸ Ibid., at 298, para. 245.

⁶⁹ See supra note 48.

⁷⁰ Nicaragua case, supra note 43, at 136–8, paras. 272–6 (with regard to the 1956 treaty of Friendship, Commerce and Navigation). See, for more details, R. Kolb, La bonne foi en droit international public: Contribution à l’étude des principes généraux de droit (2003), 283–91; Contra, H. Thirlway, The Law and Procedure of the International Court of Justice (2013), 1118.

⁷¹ According to this Judge, the Court erred in applying ‘reasonableness’ as an objective standard of review. In his view, it is not the Court's task to make ‘[a] de novo assessment of the activities of the Respondent’, but rather to ascertain whether a decision or an action is or is not ‘arbitrary’ or patently ‘out of bounds’. See Whaling in the Antarctic case, supra note 9, at 316, para. 39 (Judge Owada, Dissenting Opinion).

⁷² See CR 2013/15, at 21-23, paras. 38–45 (Lowe).

⁷³ On both dimensions of the principle, see Kolb, supra note 70, at 111 and 134.

⁷⁴ See Whaling in the Antarctic case, supra note 9, at 303–4, paras. 9–12 (Judge Owada, Dissenting Opinion) and Fitzmaurice, supra note 54, at 44–7. In the preamble to the ICRW, the state parties make clear their intention to ‘conclude a convention to provide for the proper conservation of whale stocks and thus make possible the orderly development of the whaling industry’.

⁷⁵ Whaling in the Antarctic case, supra note 9, at 252, para. 58.

⁷⁶ On the difference between the two kinds of purposes see R. Kolb, Interprétation et création en droit international public: Esquisse d'une herméneutique juridique moderne pour le droit international public (2006), 538.

⁷⁷ I am basing myself on Kolb's analysis dealing with sanctions and counter-measures, which, in my view, contains a conceptual framework that is useful to assess proportionality in international law (see Kolb, R., ‘La proportionnalité dans le cadre des contre-mesures et des sanctions – essai de clarification conceptuelle’, in Forlati, L. Picchio and Sicilianos, L.A. (eds.), Economic Sanctions in International Law: Les sanctions économiques en droit international (2004), 379 CrossRefGoogle Scholar at 380). In the context of international human rights law, see Arai-Takahashi, Y., ‘Proportionality’, in Shelton, D. (ed.), The Oxford Handbook of International Human Rights Law (2013), 446 Google Scholar. The latter author underlines that human rights courts – with the possible exception of the Inter-American Court of Human Rights – normally focus their proportionality assessments on the third limb of the principle.

⁷⁸ See, for instance, Art. 51(5)(b) of the 1977 Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the protection of victims of international armed conflicts (Protocol I), 1125 UNTS 3.

⁷⁹ In this case and many others before Whaling, the Court had barely used the term ‘standard of review’. See Oil Platforms (Islamic Republic of Iran v. United States of America), Merits, Judgment of 6 November 2003, [2003] ICJ Rep. 161, at 234, para. 33 (Judge Higgins, Separate Opinion).

⁸⁰ Nicaragua case, supra note 43, at 114, para. 224 (emphasis added).

⁸¹ Ibid., at 141, para. 282.

⁸² Elettronica Sicula S.P.A. (ELSI) (United States of America v. Italy) case, supra note 7, at 76–7, para. 129.

⁸³ Ibid., at 76, para. 128 (emphasis added).

⁸⁴ Ibid., at 74, para. 124.

⁸⁵ It was probably for this reason that the Court concluded that, ‘[t]he Respondent has not violated the FCN Treaty in the manner asserted by the Applicant . . .’ (supra note 7, at 81, para. 136. For more details, see Cannizaro, supra note 16, at 451.

⁸⁶ Dispute Regarding Navigational and Related Rights (Costa Rica v. Nicaragua), Merits, Judgment of 13 July 2009, [2009] ICJ Rep. 213, at 253, para. 101.

⁸⁷ Such measures included the requirement for Costa Rican vessels to stop at any Nicaraguan post along the river and to require their passengers to carry passports, as well as the requirement that Costa Rican riparians obtain visas to navigate the river.

⁸⁸ Dispute Regarding Navigational and Related Rights (Costa Rica v. Nicaragua) case, supra note 86, at 257–8, paras. 111–18.

⁸⁹ Ibid., at 269, para. 137.

⁹⁰ Ibid., at 289, para. 211.

⁹¹ Kolb, supra note 77, at 384.

⁹² See mutatis mutandis Shany, supra note 22, at 910–11. In Certain Questions of Mutual Assistance in Criminal Matters (Djibouti v. France), the Court had to deal with a more delicate situation: the failure by French judicial and governmental authorities to execute an international letter rogatory for the purposes of investigation of a criminal case in Djibouti. While the Court's judicial review was limited for reasons related to the protection of French ‘essential interests’, it was nonetheless facilitated by the obligation enshrined in Art. 17 of the 1986 Convention on Mutual Assistance in Criminal Matters to state reasons for the decision (Certain Questions of Mutual Assistance in Criminal Matters (Djibouti v. France), Merits, Judgment of 4 June 2008, [2008] ICJ Rep. 177, at 229–33, paras. 145–56). No reference was made to ‘reasonableness’ in this case.

⁹³ Legal Consequences of the Construction of a Wall in the Occupied Palestinian Territory, Advisory Opinion of 9 July 2004, [2004] ICJ Rep. 136, at 192, para. 136.

⁹⁴ Ibid. See the 1966 International Covenant on Economic, Social and Cultural Rights, 993 UNTS 3.

⁹⁵ Dispute Regarding Navigational and Related Rights (Costa Rica v. Nicaragua), supra note 86, at 258–9, para. 119.

⁹⁶ In my view, those previous cases had been decided on the basis of some kind of legal parameter that can defined as a standard of review. Thus, I disagree with the view that such cases had been decided without such a standard, as sometimes is suggested (see, for instance, Foster, supra note 15, at 5).

⁹⁷ With regard to the ELSI case, see Cannizaro, supra note 39, at 176. The expression does not appear either in Oil Platforms (Iran v. United States), another decision dealing with judicial control of state discretionary powers. In that judgment the Court affirmed, with regard to the customary rule on self-defence, that, ‘the requirement of international law that measures taken avowedly in self-defence must have been necessary for that purpose is strict and objective, leaving no room for any “measure of discretion”’ (Merits, Judgment of 6 November 2003, [2003] ICJ Rep. 161, at 196, para. 73).

⁹⁸ See in particular Gros, supra note 14, at 593–606, who criticizes the conceptual ambiguity of the term. In my opinion, the Court's qualification of ‘reasonableness’ as ‘objective’ had one main purpose: to avoid the question of Japan's ‘subjective’ intentions in planning and implementing JARPA II, which according to Australia and New Zealand was a disguised ‘commercial’ programme. On this question, see Whaling in the Antarctic case, supra note 9, at 438 (Judge Bhandari Separate Opinion).

⁹⁹ On the burden of proof before the Court, see del Mar, supra note 57, at 98.

¹⁰⁰ On this rule, see Kolb, supra note 76, at 673–87.

¹⁰¹ By ‘asymmetric’ I mean that the Court reversed the burden of proof with regard only to the specific question of the feasibility of non-lethal methods, and not with regard to other elements of JARPA II. See Fitzmaurice, supra note 54, at 93 and especially Foster, supra note 96, at 7–8.

¹⁰² Whaling in the Antarctic, supra note 9, at 270, para. 98.

¹⁰³ Ibid., at 335, paras. 47–8 (Judge Abraham, Dissenting Opinion).

¹⁰⁴ Ibid., at 284, para. 193.

¹⁰⁵ Ibid., 284-285, para. 195.

¹⁰⁶ Ibid., at 289, para. 211 (emphasis added).

¹⁰⁷ Gros, supra note 14, at 615–19.

¹⁰⁸ For instance, in the ELSI case, a key element in rejecting US’ claims had been precisely the fact that the respondent had given a coherent reason to justify its behaviour (ELSI case, supra note 7, at 396–7, para. 129).

¹⁰⁹ For a detailed analysis, see Corten, supra note 8, at 403–25. See also Ioannides, M., ‘Beyond the Standard of Review: Deference Criteria in WTO Law and the Case for a Procedural Approach’, in Gruszczynski, L. and Werner, W. (eds.), Deference in International Courts and Tribunals, Standard of Review and Margin of Appreciation (2014), 104 Google Scholar–6.

¹¹⁰ Obviously, the Wall advisory opinion was not a contentious case and cannot be approached purely under a ‘burden of proof’ logic. However, in many ways, that opinion can be assimilated to a contentious case, or at least the analysis carried out therein is relevant for issues of burden of proof. See also Gabčíkovo-Nagymaros Project case, supra note 48, at 40–1, para. 52 (with regard to ‘reasonableness’ and state of necessity under the law of state responsibility) and Oil Platforms case, supra note 79, at 196, para. 73.

¹¹¹ This is explained in the Dissenting Opinion of Judge Tanaka in the South West Africa cases with regard to the policy of apartheid and the prohibition of discrimination (South West Africa cases, supra note 51, at 309–10 (Judge Tanaka, Dissenting Opinion)).

¹¹² MacCormick, supra note 54, at 180–6.

¹¹³ See in particular Whaling in the Antartic case, supra note 9, at 342 (Judge Bennouna, Dissenting Opinion).

¹¹⁴ Arai-Takasashi, supra note 77, at 467.

¹¹⁵ G. Schwarzenberger, ‘The Fundamental Principles of International Law’ (1955) 87 RCADI 191, at 326.

¹¹⁶ Tully, supra note 14, at 546. See, more generally, Besson, supra note 22, at 430–3.

¹¹⁷ As one may argue with regard to the scientific dispute underlying the Whaling case (see mutatis mutandis Shany, supra note 22, at 913).

¹¹⁸ See Gros, supra note 14, at 619–20.