International Investment Law Journal
Volume 6, Issue 1, February 2026
Table of Contents
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- Associate professor Cristina Elena POPA TACHE
Editorial On Sovereignty, Transition and the New Grammar of InvestmentAbstract:This editorial examines the increasingly evident interdependence between international investment law, sustainable development and the transformations brought about by digitalisation and contemporary geopolitical instability. Traditional investment governance, focused on capital protection and dispute resolution, must now also be assessed in relation to its contribution to achieving the Sustainable Development Goals and strengthening the resilience of strategic sectors. Particular attention is paid to the need for more coherent legislation, designed to reconcile investor protection, states’ regulatory autonomy, social responsibility and long-term public interests. The editorial highlights the fact that current investment policies are increasingly interfering with the energy transition, technological innovation, critical infrastructure and economically sensitive sectors from a security perspective, which in some ways calls for a more proactive and multidimensional legal approach. Today is a time and a place where legal instruments, methods of interpretation and institutional priorities should be reformed so that international investment law can be more effective.
Keywords:international investment law, sustainable development, digitalisation, geopolitical instability, regulatory autonomy, investor protection, adaptive governance, resilience.
JEL Classification:K22, K33
DOI: 10.62768/IILJ/2026/6/1/01
Please cite this article as: Popa Tache, Cristina Elena, ‘Editorial. On Sovereignty, Transition and the New Grammar of Investment’, International Investment Law Journal 6, issue 1 (February 2026): 5-13.
Page 5 - Senior lecturer Chamundeeswari KUPPUSWAMY
Can Special Purpose Vehicles plug the Sovereignty Gap in Climate Finance for Post-conflict Regions?Abstract:This article examines how the state-centric characteristic of international climate finance creates access barriers for non-sovereign territories, such as the Kurdistan Region of Iraq and Northern Syria. Although these entities are not formally excluded from all climate funds, they are presented in the paper having regard to their limited international status, inconsistent governance arrangements, and strained relations with internationally recognised central authorities, a fact which significantly restricts direct and predictable access to adaptation and mitigation finance. The article finds that this institutional deficit also weakens the conditions necessary for stable green investment. Drawing on selected doctrines regarding effective control, functional international capacity, and investment structuring, the paper develops the concept of a limited functional legal personality for non-sovereign actors in the field of climate finance. On this basis, it analyses whether specially designed investment vehicles, including special purpose vehicles, would contribute to channelling green foreign direct investment, to the development of small-scale projects, and to mitigating some of the legal and political risks associated with contested governance. The conclusion that follows is that a carefully delimited functionalist approach would complement, without replacing, the state-based structure of the Paris regime, while also contributing to the strengthening of climate resilience and investment viability in territories characterised by political complexity.
Keywords: international investment, climate finance, functional legal personality, effective control principle, special purpose vehicle, climate action, post conflict regions.
JEL Classification: K22, K32, K33
DOI: 10.62768/IILJ/2026/6/1/02
Please cite this article as:
Kuppuswamy, Chamundeeswari, ‘Can Special Purpose Vehicles plug the Sovereignty Gap in Climate Finance for Post-conflict Regions?’, International Investment Law Journal 6, issue 1 (February 2026): 14-26.
Page 14 - Associate professor Paulo DE BRITO
Reflections on the Legality of Trump’s Tariffs from an International Investment Law PerspectiveAbstract:After a federal appeals court decided the International Emergency Economic Powers Act invoked by Trump could not legally justify the imposition of tariffs, the case is now in the hands of the Supreme Court of the United States. In U.S. constitutional history, taxes have traditionally belonged to Congress for consideration. In this paper I will address the legal arguments which are at stake and some possible implications for the current trade war. The study asks whether the unilateral imposition of tariffs under an expansive interpretation of emergency powers may trigger State responsibility under applicable bilateral investment treaties and customary international law standards, including fair and equitable treatment, indirect expropriation, and non-discrimination obligations. Using doctrinal analysis and selected case law, the paper argues that while States retain regulatory autonomy in matters of economic security, the systemic expansion of executive tariff authority risks blurring the boundary between legitimate regulatory action and Treaty-inconsistent economic coercion. The implications extend beyond U.S. constitutional law, potentially affecting the current trade war and the stability of the global investment regime.
Keywords: tariffs, national security exception, fair and equitable treatment, indirect expropriation, trade war, executive powers.
JEL Classification: K22, K33
DOI: 10.62768/IILJ/2026/6/1/03
Please cite this article as:
De Brito, Paulo, ‘Reflections on the Legality of Trump’s Tariffs from an International Investment Law Perspective’, International Investment Law Journal 6, issue 1 (February 2026): 27-36.
Page 27 - PhD. candidate Makda Gebru HAYLE
The Role and Significance of Host States’ Due Diligence Obligation in Interpreting the Standard of Fair and Equitable TreatmentAbstract:This Article explores the function and importance of the obligation of a host state’s due diligence in interpreting and applying the standard of Fair and Equitable Treatment by arbitral tribunals. It aims at addressing the controversy of the application of the obligation of due diligence when the wrongful act is committed by the host state itself. The research is based on international legal documents, investment agreements, and arbitral awards pertinent to the topic. Additionally, this study is predicated on the work of many authors who have discussed the two legal concepts – the obligation of due diligence and the standard of FET – in their books and articles. According to the findings of the study, the obligation of the host state’s due diligence is a key component in providing context for the standard of FET. Further, it is the source of the FET standard, through being one of the components of the Minimum International Standard under Customary International Law. The study highlights the importance of the host state’s due diligence when interpreting the standard of FET from three different angles. First, it discusses when the FET standard is interpreted by considering its historical origins; second, it examines the relationships between FET and Full Protection and Security (FPS), and its implications for the application of the obligation of host states’ due diligence in interpreting the standards of FET thereof. Thirdly, it examines how the gradually developed FET standard’s features and structures reflect the application of due diligence in interpreting the standard of FET. Further, this study acknowledges the role of international investment law in the development of the concept of the obligation of due diligence generally, particularly for its second wing, the ‘obligation to abstain’ under international law.
Keywords: the obligation of due diligence; the obligation to abstain; the standard of fair and equitable treatment; the standard of full protection and security; minimum international standard; host state’s conduct.
JEL Classification: K22, K33
DOI: 10.62768/IILJ/2026/6/1/04
Please cite this article as:
Hayle, Makda Gebru, ‘The Role and Significance of Host States’ Due Diligence Obligation in Interpreting the Standard of Fair and Equitable Treatment’, International Investment Law Journal 6, issue 1 (February 2026): 37-53.
Page 37 -
Senior lecturer Radu ȘTEFĂNUȚ; Professor Tomáš PERÁČEK; Professor Ľubica BAJZÍKOVÁ
Penal Norms as Structural Correctives in International Investment LawAbstract:The article observes the role of criminal norms as structural corrective mechanisms in international investment law, marked by the questioning of the legitimacy of ISDS and the intensification of corporate responsibility requirements. It draws on recent case law and regulatory developments in the fight against corruption, money laundering, transnational fraud and violations of Environmental, Social and Governance (ESG) standards. Thus, criminal law norms, which until now functioned exclusively as external repressive instruments, have begun to manifest themselves as factors of rebalancing between investor protection and the public interests of states. Methodologically, the research combines doctrinal analysis, examination of arbitration practice, and evaluation of recent legislative trends. The results indicate the positive effect of criminal law in the structure of investment treaties, contributing to the consolidation of the clean investment standard, the limitation of abuse of rights and the strengthening of the coherence of the fragmented international legal order. The conclusion supports the need to explicitly establish criteria of criminal legality in the assessment of jurisdiction and substance in investment arbitration.
Keywords: criminal law, international investment law, Investor–State Dispute Settlement (ISDS), corporate criminal liability, investment legality, legal fragmentation, international public order.
JEL Classification: K14, K22, K33
DOI: 10.62768/IILJ/2026/6/1/05
Please cite this article as:
Ștefănuț, Radu, Tomáš Peráček & Ľubica Bajzíková, ‘Penal Norms as Structural Correctives in International Investment Law’, International Investment Law Journal 6, issue 1 (February 2026): 54-67.
Page 54 - Adjunct professor Bayo ADARALEGBE
Book Review: Nigerian Foreign Investment Law and Policy, 2nd Edn., 2021 by Emmanuel I. KachikwuAbstract:This book review examines Nigerian Foreign Investment Law and Policy by Emmanuel I. Kachikwu, situating the work within the broader evolution of public international law governing the treatment and protection of foreign investment. It begins from the foundational principle of state sovereignty and the prerogative of states to regulate the admission and operation of foreign investors within their territory. The review then contextualises the transformation of investment protection through key historical developments, including the shift from the protection of “aliens” to the protection of corporate investments, the global expansion of the capitalist economic model, decolonisation, and the ideological tensions of the Cold War. Against this backdrop, Kachikwu’s analysis is critically assessed in light of the relationship between sovereignty, expropriation, the international minimum standard of treatment, and the quest for legal stability in a geopolitical environment where Western investments were often vulnerable in newly independent states. The review highlights the book’s continuing relevance for understanding Nigeria’s foreign investment regime and for contemporary debates on the balance between regulatory autonomy and the legal protection of foreign capital.
Keywords: foreign investment law, state sovereignty, international minimum standard, expropriation, decolonisation, Nigeria, investment protection, investment policy, public international law, legal stability.
JEL Classification: K22, K33
DOI: 10.62768/IILJ/2026/6/1/06
Please cite this article as:
Adaralegbe, Bayo, ‘Book Review: Nigerian Foreign Investment Law and Policy, 2nd Edn., 2021 by Emmanuel I. Kachikwu’, International Investment Law Journal 6, issue 1 (February 2026): 68-83.
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