Abstract
This study explores why the implementation of domestic environmental policies that tackle transboundary air pollution has been undermined by comparing the cases of the Republic of Korea (Korea) and Singapore. Heavy smog recurs in Korea and Singapore every year despite various attempts to reduce air pollution through the signing of environmental cooperation agreements and the introduction of domestic measures. While existing scholarship has examined intergovernmental cooperation aimed at mitigating transboundary air pollution, this study focuses on domestic factors affecting policy implementation processes at the national level. How do domestic factors shape governmental policy actions within environmental cooperation agreements in the cases of Korea and Singapore? I employed a process-tracing method to analyze the entanglement of domestic stakeholders from the late 1990s to 2019. By drawing upon domestic politics theory, I find that domestic dynamics, intricately linked to other stakeholders, have limited the effectiveness of policies implemented to address poor air quality. This finding suggests that domestic politics play a critical role in establishing effective regional environmental cooperation in the long run.