The aim of the study was to identify the legal mechanisms through which competition between the United States, China and the EU is altering the substance and institutional implementation of international law. The methodology was based on conceptual-legal, formal-legal, doctrinal-legal, comparative-legal and comparative analysis methods, applied to the study of the international legal order and models of global governance of the United States of America, China and the EU. On the basis of international legal instruments, strategic and conceptual documents of the United States of America, China and the EU, official materials and specific legislation, it has been established that, in a multipolar world, international law retains its significance as a common language of legitimacy; however, the ways in which it is interpreted, applied and institutionally reproduced are determined by competition between various centres of normative influence. Competition between these actors alters the international legal order not through a rejection of international law, but through different ways of interpreting, applying and institutionally reproducing it. The American model exacerbates the fragmentation of the legal order by extending the category of “rules” beyond formally binding international law to include sanctions, secondary restrictions, export controls and coalition mechanisms. Key trends in the transformation of the Chinese model have been identified, linked to the prioritisation of sovereignty, non-interference, development, institutional representation of non-Western states, and opposition to extraterritorial sanctions. It has been demonstrated that the European model influences the international legal order through the juridification, institutionalisation and external dissemination of digital, climate, trade and human rights standards. An analysis of the practical manifestations of these models has revealed their differing legal natures: the US employs coercive normative influence, China utilises domestic anti-sanctions mechanisms with external effects, and the EU relies on the regulatory diffusion of norms through access to the European market. The study has shown that the international legal order of the 21st century is becoming polycentric, as normative, interpretative and institutional power is being redistributed among the American, Chinese and European models of global governance. The practical significance lies in the possibility of using the results to analyse sanctions policy, digital regulation, the reform of international institutions and the legal assessment of models of global governance