IIAs represent expressions of sovereignty through which states assume reciprocal obligations in the field of foreign investment. However, the jurisprudence of investment tribunals shows that the application of IIAs may be concerned with almost any manifestation of public authority and thus ultimately with a wide array of aspects of human life.^[1] This broad reach of the international investment regime carries significant legal implications. Depending on the relevant treaty provisions and the facts of the case, the law applicable to the resolution of investment disputes may extend well beyond the applicable IIA to provisions of the host state’s domestic law, non-investment treaties, and general international law.^[2] Moreover, IIAs must be interpreted and applied “within the framework of the entire legal system prevailing at the time of interpretation.”^[3]

However, the increasing interconnectedness of IIAs with other branches of the international legal regime calls for a more fundamental reflection on their role. International investment law has become a key institution of international governance. As such, it has the potential to contribute, both directly and indirectly, to the realization of broader common interests of the international community beyond merely promoting investment flows, such as the protection of the environment or the respect for the rule of law at the international level.

International investment law is being called upon to assume a broader role during revolutionary times for international law. The recent advisory opinions of the International Tribunal for the Law of the Sea,^[4] the Inter-American Court of Human Rights,^[5] and the International Court of Justice mark a Copernican Revolution of the international legal order. At the core of the international legal order, and permeating all other international law obligations, is the human right to a clean, healthy, and sustainable environment, with states having obligations erga omnes in respect of, and an essential interest in, safeguarding the climate system.^[6] States have not only a right to regulate but an obligation to regulate, arising from their international law obligations to protect the climate system from significant harm resulting from anthropogenic emissions.^[7] Within this new paradigm, the traditional principle of equity is revitalized through the lens of intergenerational equity, under which the requirements of justice demand that all present activities be conducted in a manner that does not jeopardize the dignified living conditions of future generations.^[8]

The film

I watched the documentary film The Tribunal with the recent paradigm shift in the international legal framework in mind. It presents a powerful account of an investment dispute from a perspective seldom considered by investment tribunals—namely, that of the local communities directly affected by the investment project. Admittedly, investment tribunals are increasingly hearing and deciding arguments about whether local communities were adequately consulted. However, these arguments are generally made by the investor and/or the host state, not directly by the communities themselves. The film demonstrates how these two perspectives, even when considered together, do not necessarily reflect the views of the local communities themselves. Therefore, the first lesson one can draw from the film is that, to gain a complete understanding of the reality on the ground, arbitral tribunals may need to find ways to listen to other voices beyond the parties to the dispute. This does not mean that the voices of local communities will necessarily be decisive, but it means that those voices matter. In certain circumstances, investment tribunals may need to be proactive in ensuring that the voices of local communities are heard. This may involve not only hearing witnesses from these communities proposed by the parties or accepting amicus curiae briefs submitted on their behalf but also taking motu proprio steps to ascertain and consider those voices.

A second lesson one can draw from the documentary concerns due process and the prohibition of violence. An investor must always adhere to the due process of law when seeking to defend its investment, and under no circumstances may it resort to violence for that purpose. IIAs are said to have displaced gunboat diplomacy. Consequently, the use of hostile measures—whether by the home state or the investor—is incompatible with modern international investment law. Of course, the host state must also observe due process when taking measures that affect foreign investments.

Finally, the documentary vividly highlights the fundamental importance of protecting the environment, not just as an abstract concept, but as the very foundation of human existence. The land, water, animals, plants, and all elements that constitute the environment are not only vital resources necessary for survival, but they also shape our individual and collective identities. Destroying the environment means destroying a common heritage that no generation owns, and that cannot be owned. Therefore, the challenge we face is to work toward an international investment regime that does not hinder, but rather facilitates and reinforces, the right and duty of states to protect the environment and human rights, “without undermining the legal certainty and predictability that international investment agreements seek to provide.”^[9]

Author

Gabriel Bottini is Adjunct Professor of Public International Law, University of Buenos Aires, and Partner at Uría Menéndez.

Note

The Tribunal, Directed by Malcolm Rogge, Produced by Columbia Center on Sustainable Investment, 2023.

^[1] This is not to overstate the importance of IIAs. Whether they contribute to the promotion of investment flows or economic development, their direct impact on everyday life is limited at best. However, this limitation is not unique to international investment law. We live in a world where, unfortunately, even the most fundamental principles of international law often appear to have limited influence on the conduct of relevant actors in the international arena.

^[2] See in relation to climate change treaties: Obligations of States in respect of Climate Change (Advisory Opinion) (International Court of Justice, General List No 187, 23 July 2025) (“ICJ Climate Change Advisory Opinion”), para. 170.

^[3] Legal Consequences for States of the Continued Presence of South Africa in Namibia (South West Africa) notwithstanding Security Council Resolution 276 (1970), Advisory Opinion, I.C.J. Reports 1971, p. 31, para. 53.

^[4] Request for an Advisory Opinion submitted by the Commission of Small Island States on Climate Change and International Law, ITLOS Case No. 31, Advisory Opinion, 21 May 2024.

^[5] Advisory Opinion OC-32/25 on the Climate Emergency and Human Rights (Interpretation and scope of Articles 1(1), 2, 4(1), 5(1), 8, 11(2), 13, 17(1), 19, 21, 22, 23, 25 and 26 of the American Convention on Human Rights; 1, 2, 3, 6, 7, 9, 10, 11, 12, 13, 14, 15, 16, 17 and 18 of the Additional Protocol to the American Convention on Human Rights in the Area of Economic, Social and Cultural Rights “Protocol of San Salvador,” and I, II, IV, V, VI, VII, VIII, XI, XII, XIII, XIV, XVI, XVIII, XX, XXIII, and XXVII, of the American Declaration of the Rights and Duties of Man), Advisory Opinion OC-32/25 of the Inter-American Court of Human Rights, 29 May 2025 (“IACtHR Climate Emergency Advisory Opinion”).

^[6] ICJ Climate Change Advisory Opinion, paras. 393, 440.

^[7] Ibid., para. 428.

^[8] Ibid., paras. 152–157.

^[9] IACtHR Climate Emergency Advisory Opinion, para. 163.

Photo: Malcolm Rogge interviews Intag nature defender, Julio Espinosa.