The rules-based international order faces an existential paradox. Eight decades after its founding, international law has never been more vital to human flourishing, yet it has also never been more imperilled. Developments in recent years such as the invasion of Ukraine and the erosion of the multilateral trading system represent more than institutional failures – they expose critical fault lines that, if left unaddressed, threaten to fracture the foundational architecture of international law. This article explores what these trends reveal about the future of the international rule of law and contends that the way forward requires a spirit of sober optimism – one that neither abandons hope nor ignores hard realities about the existing legal order. It suggests that this approach represents our best hope for securing humanity’s shared future.

The steadily growing reliance on international dispute settlement as environmental protection means is not uncontroversial, raising three sets of issues regarding: (i) the nature of adjudicative fora (ontological issues); (ii) wider assumptions and frameworks (methodological issues); and (iii) processes for creating and implementing environmental obligations (processual issues). Accordingly, this review essay is threefold. Despite a trend towards greater reliance on international dispute settlement fora, Part I discusses whether their presumably inherent ‘anthropocentric’ orientation hinders their suitability and assesses the feasibility of solutions advocated in judicial discourses. Having observed inconsistencies between the law-ascertainment methods deployed by adjudicative fora and the general regimes on law-ascertainment, Part II contends, international law-based environmental protection risks becoming overly “judge-centric”, despite international law-making’s state-centric nature. Part III concludes considering various reversals of perspective, potentially countering the shortcomings of overly “judge-centric” environmental protection, in addition to factors such as enforceability, plausibly justifying greater reliance on arbitral fora.

This paper explores how unrecognised separatist entities in Eurasia – de facto regimes such as Transnistria, South Ossetia, Abkhazia, Nagorno-Karabakh, and the Donetsk and Luhansk People’s Republics – engage with international law. It examines whether, and to what extent, these regimes comply with international law, analysing court decisions and legislation to move beyond simplistic views of non-recognition or assumed legality. The findings reveal that de facto regimes tend to mirror the international law approaches of the states they are most closely connected to – whether the territorial state (e.g. Ukraine) or an outside state exercising effective control over the entity (e.g. Russia or Armenia). This pattern is explained by the theory of “acculturation to statehood”: through sustained legal and institutional interaction, these regimes internalise and replicate the legal systems of their reference states. The study contributes to a more nuanced understanding of the role of de facto regimes in the international legal order.