Kai Schulze, Jale Tosun

• The literature on international regulatory regimes has highlighted how rival standards can create different points of convergence. Scholarly attention has also focused on how the European Union (EU) and the United States (USA) attempt to ‘export’ their environmental standards internationally. Here, we explore the effectiveness of these attempts by means of third states' decisions to ratify the Cartagena Protocol on Biosafety to the Convention on Biological Diversity, a multilateral environmental agreement regulating genetically modified organisms that is promoted by the EU but opposed by the USA. Our findings confirm that both rivals are able to influence the ratification decision of states, but they also suggest that these effects may have different origins. Countries relying more heavily on US markets for food exports tend to be less likely to ratify the Cartagena Protocol, while countries that have applied for EU membership are more likely to ratify the protocol.