This chapter examines the mounting challenges confronting the international tax regime in a context of profound global instability. Intensified socioeconomic inequalities, accelerated globalisation, and the structural transformations of the digital economy have underscored the inadequacy of tax frameworks that remain largely rooted in early twentieth-century agreements. Despite recent reforms led by the OECD and the G20—most notably the BEPS project and the Two-Pillar Solution—current regulations continue to privilege advanced economies while leaving the fiscal needs of developing countries insufficiently addressed. Against this backdrop, the UN has initiated negotiations towards a Framework Convention on International Tax Cooperation. This initiative seeks to establish a more inclusive and equitable platform for global tax governance, broadening participation beyond the OECD and strengthening the role of developing economies. Nevertheless, while the UN proposal represents a significant step towards legitimacy and universality, its capacity to generate concrete and enforceable outcomes remains uncertain.