This article examines the contested identity of a particular group of Viet-kieu, who were born in China and who returned to Vietnam in the 1970s, by looking into their personal histories, descent backgrounds and the political and socio-economic processes they lived through in the past few decades. Unlike other Viet-kieu who returned from the West, the Viet-kieu in the borderlands rarely received any attention from the media or academia. They led a double life both in China and in Vietnam and experienced dramatic changes of fate from the 1970s, through the 1980s, to the 1990s. Their hybrid cultural endowment and cross-border familial ties were both detrimental and beneficial to their social and economic life within different historical contexts. Reopened borders around the world in the post-Cold War era have generated discourses on transnational economic integration, regional connectedness, as well as fluid mobility and identities. It has become a fashion to criticize the study of culture and identity as rigid entities, while the increasing stress on subjectivity and agency has made identity seem ever more evolving and changing. Putting aside the romantic notion of fluid and multiple identities, this article brings up a number of empirical cases to illustrate how identity is often shaped by the possibilities and constraints under different politico-economic circumstances.