The new dynamics on the border epitomize how the escalation of the Vietnam War and the Cultural Revolution compounded the already wobbly state building campaign at the border. During the decade from 1965 to 1975, the war and the chaotic sociopolitical movement militarized the Sino-Vietnamese border and made this far-off region more relevant to the decision-making in Beijing and Hanoi about their internal power struggles and national security policies. Yet, these developments also shifted state-society relations on the political periphery in favor of a more porous boundary. Thus, the extension and contraction of state power took place simultaneously. Both Chinese and Vietnamese authorities launched ambitious infrastructure projects in the border area to facilitate the transportation of aid to Vietnam and mobilized the local society against the possible expansion of the war. The Sino-Vietnamese land and maritime border region, as well as the transportation lines running through it, became spaces of frequent interactions between the Chinese and Vietnamese officials regarding the provision of aid and the coordination of border defenses. The efficiency of these interactions, however, was increasingly susceptible to the decline of the Sino-Vietnamese partnership following the Tết Offensive and the start of negotiations between Hanoi and Washington in 1968.

Shifting focus from the Sino-Vietnamese borderlands to the northern Gulf of Tonkin during the decade from the end of the First Indochina War to the escalation of the Vietnam War, this chapter views the history of state building from the seashore. Echoing land reforms and agricultural collectivitization on the borderlands, fishery reforms and collectivization toppled the existing economic and social structure and tightened states’ control over fishery labor and catches. The “joint state invasion” culminated in the bilateral fishing agreement in 1957 and a collaborative survey of natural resources in the Gulf. The fact that the centralization of resource control and flows took place almost simultaneously along the Chinese and Vietnamese coasts left the fisherfolk with little leeway to avoid encountering the state. The characteristics of the reform programs and the geographic, technical, and social realities of the locality nevertheless obstructed the political centers’ endeavors to establish primacy along the coastal frontier. This chapter demonstrates that the tensions between internationalist, nationalist, and transnational local agendas were greater at the maritime border than on the borderlands.The defining policies of a communist revolution encountered more determined resistance from the seafaring people whose livelihood relied on an open and integrated maritime space.