Based on analysis of legal documents on family reunification and educational material concerning transnational adoption in Denmark, this article suggests that the concept of attachment may be conceptualized as a specific operationalization of belonging, and that belonging and biopower may be viewed as intertwined (rather than opposites). The analysis conceptualizes two modes of how belonging is operationalized through attachment. The belonging of families seeking reunification is targeted on a regulatory level via the legal requirement of national attachment. This requirement materializes as a prognosis of belonging in families seeking reunification. On a disciplinary level, psychological attachment discourse is utilized to address belonging in adoptive kinship. As a disciplinary instrument, psychological attachment discourse extracts affective labour from the adoptee in order to secure belonging in the form of psychological attachment, which serves to sustain the white adoptive family. In both cases, attachment discourse naturalizes the governing of belonging over time.