OBLIGATIONS IN INTERNATIONAL TRADE AND INVESTMENT LAW.

In recent years, environmental, social and governance (ESG) standards have taken on a level of importance that the original designers of the international trade and investment system did not anticipate. Most of the current frameworks were built with the goals of market access and investor protection at the forefront, leaving states with limited clarity on how far they may regulate for sustainability without breaching international commitments. As governments now push forward with climate legislation, mandatory human rights due diligence and broader supply chain oversight, friction with long standing treaty obligations is becoming more visible. This article explores how these tensions emerge and asks whether existing legal structures are capable of adapting to the demands of ESG driven regulation. By examining WTO case law, recent treaty drafting practices and decisions from investor State disputes, the article finds that the legal system already contains some tools that can support sustainability objectives though they are unevenly applied and often subject to narrow interpretation. Newer treaties show an increasing willingness to incorporate ESG language directly into binding obligations, signalling an ongoing shift from voluntary corporate social responsibility to more enforceable standards. Despite this development, the lack of common approaches across trade and investment regimes creates risks of fragmentation and uneven implementation, especially for developing countries with limited regulatory capacity. The article argues that without clearer interpretive guidance and more deliberate treaty design, conflicts between economic rules and sustainability goals will continue to arise. It concludes that integrating ESG considerations into international economic law is both necessary and achievable, but it requires reforms that align legal obligations with the broader global movement toward responsible and sustainable economic activity.