Learning from the Montreal Protocol to improve the global governance of antimicrobial resistance.

The Montreal Protocol has played a critical role in promoting global collective action to phase out the use of ozone-depleting substances, ultimately preventing millions of cases of skin cancer, cataracts and other health issues related to ultraviolet radiation exposure. This success entails transferable lessons for coordinated action required to improve the global governance of other challenges. Like ozone depletion, antimicrobial resistance (AMR) is a challenge of the global commons, requiring coordinated actions across human, animal and environmental sectors. We identify equity, flexibility and accountability as three core governance principles that underlie the success of the protocol and employ the 3-i framework to understand how interests, ideas and institutions contributed to the protocol's success. Equity-promoting strategies consisted of an inclusive negotiation process, supporting developing countries with multilateral funding and a progressive compliance model. Flexibility was built into the protocol through the development of country-specific strategies, reorienting incentive structures for industry and facilitating regular amendments in response to emerging scientific evidence. Accountability was promoted by mobilising public advocacy, establishing targets and enforcement mechanisms and conducting independent scientific and technical assessments. Applying our proposed principles presents an opportunity to improve the global governance of AMR. Finally, we acknowledge limitations to our analysis, including our focus on a single environmental treaty, significantly greater funding requirements and multifacetted stakeholder involvement in the case of AMR, differing market and incentives structures in antibiotic development and distribution, and ethical concerns with using trade restrictions as a policy tool.