Transboundary fine dust has been a leading cause of dispute between China and Korea since the mid‐2010s. This study observes that transboundary fine dust is not purely an environmental issue, but rather mixed with political and diplomatic challenges. Despite the emerging bilateral and multilateral efforts to tackle this issue, this research sheds light on how political and diplomatic factors have undermined the outcomes of environmental negotiations between China and Korea. We highlight three dimensions of policy‐based studies: scientific joint research on source‐receptor relationships, interstate environmental negotiations, and multilateral environmental institutions in Northeast Asia. This study argues that transboundary fine dust cooperation has been extensively entangled with national political interests and proceeded via diplomatic channels, leading to the current absence of binding agreements and policy commitments. Therefore, a steady process of de‐linking environmental cooperation and diplomatic fluctuations would be the best direction to proceed in a long‐term perspective.

What factors have driven South Korea

In this article, I investigate Korea's prudential environmental diplomacy with China regarding transboundary fine dust pollution from the perspective of Korea's disadvantageous position vis-à-vis China due to the ambiguity of pollution responsibilities and geopolitical constraints. Against this backdrop, Korea has tactically exercised prudential environmental diplomacy toward China in dual tracks. First, it has taken a "high-profile" stance in engaging with and socializing China into bilateral and multilateral frameworks and endeavors to align its environmental interests with those of China via scientific and technological cooperation. Second, Korea has undertaken a cautious procedure and is not pressuring China by pursuing legal-binding approaches immediately. I see a "mixed success" of Korea's environmental engagement with China and appraise Korea's policy flexibility and pragmatism.

In the wake of the intensifying Sino–Japanese rivalry in Asia, a new third-party market cooperation (TPMC) framework emerged in late 2018. The new mechanism was inaugurated around the time of former Japanese Prime Minister Shinzo Abe's visit to Beijing, displaying new attempts at Sino–Japanese economic diplomacy. Nonetheless, this article highlights the absence of major cooperative outcomes and suggests a pessimistic vision of TPMC's future, as three pairs of politico-economic gaps have led to asymmetries in the approaches adopted by China and Japan. First, a government-to-government policy asymmetry occurred between China's initiatives and Japan's responsiveness, as the latter merely utilized the TPMC as a temporary diplomatic tool to restore bilateral relations in late 2018 and appeared to have lost its policy momentum in the following years. Second, asymmetries in business modes and investment management between the two countries' enterprises have led to technical barriers in materializing the two governments' agreements into specific TPMC business collaboration. This study illustrated a project of Sino–Japanese collaboration in building a high-speed railway in Thailand, and saw this failed case as a warning for existing gaps of commercial modes. Third, both countries are now confronted with domestic underdeveloped public–private partnerships between state and private sectors. This article also aims to provide some policy-oriented implications for steadily implementing the Sino–Japanese TPMC in the future.