How do policy-oriented learning and shifting coalitions among private and public actors affect the evolution of the regulatory governance of legal and sustainable global timber commodity production and trade? To answer this question, we study the interplay between the transnational private regulation of sustainable forestry certification under the Forest Stewardship Council (FSC) scheme and the public policy requesting due diligence to prove the legality of global timber trade under the EU Timber Regulation (EUTR). We show that strategic policy-oriented learning and shifting coalitions among NGOs, business companies and state regulators were key shapers in the evolution and interplay of private and public regulations in the forest sector. In particular, environmental NGOs (ENGOs) and some forest-based industries first developed the non-state, market-driven FSC forest certification through a strategic alliance triggered by strategic policy learning about the failures and limitations of global state-based regulatory instruments. Following policy controversies about the eroding legitimacy and the ineffectiveness of FSC certification ENGOs, state regulators and other forest industries responded to these concerns and built a new strategic alliance to design and enforce regulatory bans and due diligence rules under the EUTR. Due to these controversies, shifting coalitions and strategic learning, private certification was not recognized as a green-lane to prove legality assurance under the EUTR. Nevertheless, FSC certification has been included, developed and practiced as part of the due diligence systems under the EUTR. In terms of theory development, our results show that strategic policy learning and processes of making and breaking strategic alliances were based on changes in core empirical beliefs based on evidence and information. However, these changes did not involve changes in core normative beliefs, which acted as main cognitive filters for breaking old strategic alliances and making new ones. These essentially cognitive mechanisms explain much of the evolution in regulatory governance interactions in the forest sector, shifting from public to private, then from private to public, and finally ending up in public-private controversies and adaptations.