INTRODUCTION
The International Court of Justice (hereinafter referred as ICJ) Advisory Opinion on the Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965 (hereinafter referred as Chagos Archipelago case), which was decided on 25th of February 2019 is a significant verdict on right to self-determination together with the decolonization.1 Accordingly, ICJ determined that the United Kingdom’s detachment of the Chagos Archipelago from Mauritius in 1965 was not founded upon an authentic and voluntary manifestation of the will of the affected populace, and that the process of decolonization for Mauritius was not legally finalized at the time it achieved independence in 1968.2
In recent decades, the amicus curiae role, literally ‘friend of the court’ has seen considerable development in the context of international dispute resolution.3 Originally limited to domestic systems, the amicus mechanism is now accepted in international courts to enhance decision-making through diverse perspectives.4 The Chagos proceedings highlighted influential amicus participation, prompting inquiries into its impact on the Court’s legal reasoning. In such background, this study examines how far amicus briefs have contributed to shape the ICJ’s viewpoints regarding the Chagos Advisory Opinion. This study seeks to comprehend the significance of these submissions in molding the legal reasoning and verdicts of the Court. The research examines fundamental matters regarding the sources of international law, the influence of non-state participants in court cases, and the legitimacy of international legal rulings.5 In a methodological sense, it seeks to address the difficulty of mapping causal ties between external contributions and judicial rationale, particularly noting the ICJ’s habit of not directly recognizing amici submissions.6
AMICI INTERVENTIONS BEFORE INTERNATIONAL COURT OF JUSTICE
The period spanning from the late 1990s to the early 2000s marked a time when amici briefs gained considerable traction in international law.7 The evolution of this trend stemmed from multiple influences, which encompassed the establishment of international legal institutions, the recognition of community interests in legal matters, engagement from non-state participants, and the push for clarity in the judicial process.8
Thus, ICJ shows cautiousness in relation to amici engagement. The ICJ has not formally revised its Statute or Rules to regulate amicus curiae submissions unlike other international tribunals9. Recently, the Court has become more open to receiving unsolicited input from individuals not directly involved, especially in advisory settings that feature procedural leniency.10 The core for amicus roles in advisory proceedings at the ICJ is principally founded on Article 66 of the Statute and Article 105 of the Court’s Regulations.11 Article 66 allows international organizations to provide relevant information, while Article 105 grants the Court discretion in accepting written statements from non-invited organizations.12 This establishes a discretionary framework where the Court is not mandated to accept amicus submissions and retains authority over their consideration.13
The conceptual bases for the engagement of amicus curiae are found upon several mutual rationales.14 Fundamentally, amicus briefs possess the capacity to enhance the quality of judicial decision-making by providing specialized expertise, empirical data, or contextual insights that the involved parties may neglect or fail to disclose.15 In addition, amicus involvement serves a representational purpose by empowering affected stakeholders, who do not hold formal party status in the litigation, to convey their interests and perspectives.16 This characteristic holds particular importance in the sphere of international law, wherein the established state-centric paradigm has the potential to sideline indigenous populations, non-governmental organizations, and other non-state participants whose rights are fundamentally at stake.17 In conclusion, the engagement of amicus curiae strengthens the legitimacy and democratic accountability of international adjudication by fostering enhanced involvement in judicial processes.18
CHAGOS ARCHIPELAGO DISPUTE IN NUTSHELL
The Chagos Archipelago, located in the Indian Ocean, was administered as a fundamental element of the British colony of Mauritius until 1965, when the United Kingdom detached it from Mauritius and established the British Indian Ocean Territory. This separation occurred three years prior to Mauritius attaining independence in 1968. Between the years 1967 and 1973, the United Kingdom engaged in the forcible expulsion of the entire indigenous Chagossian populace to enable the establishment of a United States military installation on Diego Garcia.19 The legal controversies associated with the Chagos Archipelago have persisted for several decades, involving matters of decolonization, self-determination, territorial sovereignty, and the rights of displaced communities.20 Mauritius has persistently asserted that the severance was unlawful and that the archipelago continues to constitute a part of its sovereign territory.21 The Chagossian community, who were forcibly removed and deprived of the chance to return, have diligently pursued a range of legal and political avenues to assert their rights.22
On June 22, 2017, the United Nations General Assembly promulgated Resolution 71/292, which sought an advisory opinion from the ICJ on two pivotal inquiries:
(a) whether the decolonization process of Mauritius was lawfully concluded upon the conferment of independence in 1968, subsequent to the detachment of the Chagos Archipelago; and
(b) what implications under international law emerge from the ongoing governance of the Chagos Archipelago by the United Kingdom.23
These investigations scrutinized core ideas tied to decolonization, self-determination rights, and the protection of territorial integrity, along with the legal outcomes of actions classified as wrongful by international standards.24
The advisory proceedings accumulated substantial international scrutiny and extensive participation. Hence, thirty sovereign states submitted written statements, in conjunction with written observations from twenty-three states, exemplifying one of the highest degrees of state participation in ICJ advisory proceedings as amici intervention.25 Beyond the formal engagement of state entities, the proceedings benefitted significantly from the involvement of non-state actors via amicus curiae submissions.26 Although the precise quantity and content of amicus briefs are not exhaustively recorded in publicly accessible ICJ documentation, scholarly analyses suggest that numerous organizations advocating for Chagossian interests, human rights entities, and academic institutions presented unsolicited materials to the Court.27
AMICI BRIEFS AND THEIR INFLUENCE TOWARDS THE ADVISORY OPINION
The amicus curiae contributions presented throughout the Chagos Advisory Opinion proceedings incorporated a broad spectrum of viewpoints and interests; however, the level of thorough documentation is restricted owing to the ICJ’s informal practices concerning amicus materials.28 The available evidence demonstrates that amicus briefs were advanced by entities representing the Chagossian diaspora, international human rights non-governmental organizations, along with academic institutions.29
The substantive focus of these amicus submissions evidently centered on several essential themes: the historical context and legal implications surrounding the forced displacement of the Chagossian population; the application of self-determination principles to the decolonization process of Mauritius; the human rights ramifications of the ongoing exclusion of Chagossians from their ancestral lands; and the discussions related to the legal repercussions of the actions performed by the United Kingdom.30The representational importance intrinsic to amicus participation warrants significant scrutiny. The Chagossian inhabitants, identified as a sidelined indigenous segment with no formal advocacy from the state, found it hard to seek direct engagement with the ICJ. Therefore, amicus briefs set up a somewhat casual framework, even if it was undefined and filled with confusion, to express Chagossian views in the Court.31
Notwithstanding the absence of overt citations or acknowledgments of amicus curiae briefs in the advisory opinion by the ICJ, a meticulous evaluation of the reasoning presented therein indicates possible channels through which amicus submissions might have enriched the Court’s insights.32 The Court’s characterization of self-determination as an essential human right, alongside its prioritization of the authentic and uncoerced expression of the will of the relevant populace, appears to reflect arguments that were likely presented in amicus briefs.33 The advisory opinion engaged in rigorous analysis of the historical background associated with the separation, including a detailed review of the negotiations conducted between the United Kingdom and Mauritius in 1965. The Court concluded that the separation did not stem from the authentic and uncoerced expression of the will of the Mauritian populace and determined that the detachment constituted a breach of territorial integrity.34
More precisely, scholarly examination suggests that amicus submissions within international judicial proceedings can exert influence on judicial reasoning even in the absence of explicit citation, by framing pertinent issues, providing contextual information, corroborating arguments posited by formal participants, or illuminating considerations that might otherwise be disregarded.35 In the case concerning the Chagos Archipelago, amicus briefs may have fulfilled these roles by reinforcing the human rights and self-determination aspects of the decolonization issues presented to the Court. Comprehending how the ICJ interacts with amicus briefs is undeniably difficult, given the Court’s pattern of avoiding clear approval of these inputs. In contrast to certain international tribunals that systematically acknowledge amicus submissions, the ICJ employs an obscuring methodology.36 The advisory opinion points out a void in clear references to amicus briefs, bypasses engaging in conversation about the submitted amicus materials, and remains vague about which submissions, if any, were seen as persuasive by the Court.37
A CRITICAL OVERVIEW
The fundamental methodological obstacle in evaluating the impact of amicus briefs on the Chagos Advisory Opinion resides in establishing causal relationships between external submissions and judicial deliberations.38 The ICJ’s practice of not explicitly referencing amicus materials renders it impossible to ascertain with certainty which arguments or information from amicus briefs the Court contemplated.39 Different viewpoints conveyed in amicus briefs could echo the stances of official parties, leading to complexity in assigning the impact specifically to amicus contributions.40
The understanding of ‘influence’ is quite elaborate and shows itself on different layers.41 Direct influence may be assessed by the Court’s incorporation of particular legal arguments from amicus briefs. Indirect impacts can manifest as the organization of matters, delivering contextual insights that improve the Court’s grasp, or affirming points made by legitimate contributors.42 Expressive influence may entail the legitimation of certain viewpoints or contribution to broader normative advancements in international law, even in the absence of immediate repercussions on the specific adjudication.43
The informal and impenetrable methodology of ICJ concerning amicus curiae evokes considerable apprehensions pertaining to transparency, procedural equity, and the legitimacy of international adjudication.44 The inadequacy of specific frameworks governing the submission, evaluation, and discourse on amicus briefs fosters ambiguity for potential amici and could prompt unequal consideration of various submissions.45 The deficiency of transparency regarding which amicus briefs the Court acquires and deliberates upon subverts public accountability.46 Comparative scrutiny elucidates that other international tribunals have addressed these apprehensions via more formalized amicus protocols.47Evaluating things normatively, the involvement of amicus curiae is key to fostering the democratization of international law.48 It empowers non-state entities to challenge state authority within global legal discussions. In situations involving decolonization, particularly regarding the Chagos dilemma, this becomes vital as it enables the affected populations to advocate for their entitlements.49
The Chagos case encourages a scholarly inquiry into the interaction between advisory opinions and public/community interest litigation as it pertains to international law. 50Advisory opinions function as mechanisms for advancing community interests, including human rights and decolonization.51 The participation of amicus curiae enhances this public interest function by promoting broader stakeholder involvement and diverse perspectives.52
CONCLUDING REMARKS
The advisory ruling by the ICJ concerning the Chagos Archipelago is a notable milestone at the merging of international law, the decolonization process, and self-determination. The participation of amicus curiae serves as a testament to the transforming responsibilities of non-state contributors within international legal structures, inciting necessary reviews of their power in judicial processes.
This examination assesses amicus curiae submissions through multiple frameworks: procedural standards at the ICJ, meaningful contributions to legal reasoning, and judicial responsiveness to these briefs. The results indicate a diverse landscape. Amicus briefs offered critical opportunities for the Chagossian people and other stakeholders to inform the Court’s discussions, fulfilling essential representational and epistemic roles. The Court’s findings on the Chagos Archipelago’s separation correspond with arguments likely presented in amicus briefs, especially concerning self-determination and affected populations’ rights.53
The way the ICJ informally handles amicus materials masks their role in shaping the Court’s conclusions. The advisory opinion does not contain explicit citations to amicus briefs or analyses of their substance, thus obscuring which arguments were deemed persuasive. This opacity hinders the evaluation of influence and raises concerns regarding procedural fairness and accountability in international law.54The Chagos case highlights the potential and constraints of amicus curiae in international law democratization. Amicus participation enhances legitimacy through stakeholder engagement and representation of marginalized populations. Achieving this potential necessitates improved procedural clarity, transparency, and judicial responsiveness from the ICJ.
The Chagos Advisory Opinion highlights potential reforms for amicus participation. ICJ must create official protocols for amicus filings, outline criteria for acceptance, mandate the recognition of submitted materials, and improve openness in evaluating amicus briefs. Such adjustments would strengthen the validity and functionality of amicus contributions, while safeguarding the Court’s judicial freedom and choices.55
The impact of amicus briefs on the Chagos Advisory Opinion transcends mere quantitative assessment. Their role is intricate, covering aspects such as information dissemination, stakeholder advocacy, enhancement of legal arguments, and their input into the progression of international law. When international courts tackle complicated public interest topics, the purpose of amicus curiae is anticipated to stay a point of contention, demanding persistent review of procedural, transparency, and legitimacy challenges.56
*****
Footnotes
1. International Court of Justice, Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965, Advisory Opinion, 2019 I.C.J. Rep. 95 (Feb. 25).
2. Abdullah Al Mamun & Md. Morshed Mahmud Khan, ICJ Advisory Opinion on Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965 (Chagos Advisory Opinion): A Critical Analysis, 34 Dhaka U. L.J. 1 (2023), https://doi.org/10.3329/dulj.v34i1.69610., Aleksandra Kuźniak, Advisory Opinion or Judgment? The Case of the Chagos Archipelago, 13 Adam Mickiewicz U. L. Rev. 39 (2021), https://doi.org/10.14746/ppuam.2021.13.03.
3. Luigi Crema, Testing Amici Curiae in International Law: Rules and Practice, 12 L. & Prac. Int’l Cts. & Tribunals 201 (2013), https://doi.org/10.1163/22116133-02201006., Dinah Shelton, The Participation of Nongovernmental Organizations in International Judicial Proceedings, 88 Am. J. Int’l L. 611 (1994).
4. Gustavo Fernandes de Almeida, International Procedural Regulation in the Common Interest: The Role of Third-Party Intervention and Amicus Curiae Before the ICJ, 18 L. & Prac. Int’l Cts. & Tribunals 256 (2019), https://doi.org/10.1163/15718034-12341399., Nienke Grossman, The Normative Legitimacy of International Courts, 86 Temp. L. Rev. 61 (2013), https://doi.org/10.2139/SSRN.2185304.
5. Grossman, supra note 5.
6. Crema, supra note 4., Almeida, supra note 5.
7. Id
8. Grossman, supra note 5, Anne-Marie Slaughter, A Global Community of Courts, 44 Harv. Int’l L.J. 191 (2003).
9. Almeida, supra note 5.
10. Sandesh Sivakumaran, Techniques and Innovations in the Taking of Evidence, in The International Court of Justice and the Judicial Function 251 (Malgosia Fitzmaurice & Christian J. Tams eds., 2013).
11. Statute of the International Court of Justice art. 66, June 26, 1945, 59 Stat. 1055, 33 U.N.T.S. 993; Rules of Court art. 105, adopted Apr. 14, 1978, as amended.
12. Almeida, supra note 5.
13. Crema, supra note 4.
14. Joseph D. Kearney & Thomas W. Merrill, The Influence of Amicus Curiae Briefs on the Supreme Court, 148 U. Pa. L. Rev. 743 (2000).
15. Victor E. Flango et al., Amicus Curiae Briefs: The Court’s Perspective, 27 Just. Sys. J. 180 (2006), https://doi.org/10.1080/0098261X.2006.10767799.
16. S. James Anaya, Indigenous Peoples in International Law (2d ed. 2004).
17. Id
18. Armin von Bogdandy & Ingo Venzke, In Whose Name? A Public Law Theory of International Adjudication (2014)., Laura Jeffery, The International Court of Justice: Advisory Opinion on the Chagos Archipelago, 35 Anthropology Today 1 (2019), https://doi.org/10.1111/1467-8322.12508.
19. Stephen Allen, Self-Determination, the Chagos Advisory Opinion and the Chagossians, 69 Int’l & Comp. L.Q. 1 (2020), https://doi.org/10.1017/S0020589319000526.
20. Id
21. Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965, supra note 2.
22. Allen, supra note 20.
23. UNGA Res. 71/292, Request for an Advisory Opinion of the International Court of Justice on the Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965 (June 22, 2017).
24. Gino J. Naldi, Self-Determination in Light of the International Court of Justice’s Opinion in the Chagos Case, 7 Groningen J. Int’l L. 216 (2020), https://doi.org/10.21827/GROJIL.7.2.216-235.
25. Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965, supra note 2.
26. Stephen Allen & Chris Monaghan, Stakeholders or Bystanders?: An Attempt by Seychellois Chagossians to Intervene in the International Tribunal for the Law of the Sea, 33 Leiden J. Int’l L. 1 (2020).
27. Id.
28. Almeida, supra note 5.
29. Allen & Monaghan, supra note 27.
30. Id.
31. Allen, supra note 20.
32. Naldi, supra note 25.
33. Id.
34. Legal Consequences of the Separation of the Chagos Archipelago from Mauritius in 1965, supra note 2.
35. Kearney & Merrill, supra note 15., Flango et al., supra note 17.
36. Crema, supra note 4.
37. Almeida, supra note 5.
38. Kearney & Merrill, supra note 15.
39. Almeida, supra note 5.
40. Crema, supra note 4.
41. Id.
42. Kearney & Merrill, supra note 15.
43. Id.
44. Almeida, supra note 5.
45. Crema, supra note 4.
46. Id.
47. Id.
48. Von Bogdandy & Venzke, supra note 19
49. Allen, supra note 20.
50. Sandrine Maljean-Dubois, The Role of Advisory Opinions in Addressing Public Interest Issues, in The International Court of Justice and the Environment 145 (Sandrine Maljean-Dubois ed., 2023), https://doi.org/10.4324/9781003433460-10., Maria Antonia Tigre et al., The Role of Advisory Opinions in International Law in the Context of the Climate Crisis: An Introduction, in The Role of Advisory Opinions in International Law in the Context of the Climate Crisis 1 (Maria Antonia Tigre et al. eds., 2024), https://doi.org/10.1163/9789004730618_002.
51. Tigre et al., supra note 51.
52. Almeida, supra note 5.
53. Naldi, supra note 25.
54. Almeida, supra note 5., Crema, supra note 4.
55. Id.
56. Grossman, supra note 5.