Covering more than a century, from the late nineteenth century to the nominal end of the Cold War, this panel weaves together four diverse presentations to reconceptualize the making of the Sino-Southeast Asian borderlands from the land to the sea. Frances O’Morchoe challenges the literature on Zomian escapism by examining British colonial strategies in the Wa region, where the state claimed sovereignty over mineral-rich territories while eschewing direct governance in order to exploit resources without investing in administrative control. Xuexin Cai traces the development of a modern regime of tropical hygiene in southern Yunnan from the Maoist to the Reform periods. It highlights how Chinese state-sponsored malaria control efforts, based on ideas of hygiene and progress that were born in temperate regions, negotiated with the dense networks of tropical socio-ecologies that extended into neighboring Southeast Asian countries. Anke Wang explores the impact of the French colonial regime's energy imperialism, epitomized by coal mining in coastal Tonkin, on local fisheries—a subsistence economy for inhabitants along the Chinese-Vietnamese maritime borderland in the Gulf of Tonkin. Junyi Han examines how unexploded ordnances (UXO) left by the Sino-Vietnamese Conflict in the 1980s served as a rogue infrastructure in Yunnan. UXO weaponized the border landscape and became violent manifestations of state sovereignty, fundamentally redefining the relationship between border residents and the environment.

From landmines to malaria, fisheries to colonial governance, the panel sheds new light on how borders – both as physical and conceptual entities – function as a liminal space continually negotiated through the interplay of human activities, natural forces, and state interventions. This panel invites a broad audience interested in environmental history, borderlands studies, decolonization studies, and science and technology studies to engage with the essential question of how borders operate as dynamic spaces that both constrain and enable grassroots mobility, socio-ecological resilience, and state control.