This chapter critically examines the complex nexus between migration and security in South Asia, highlighting the (i) temporal dynamics shaping this relationship, (ii) a paradoxical dynamics of causing “displacement” and politico-legal refugee hosting politics aspects of dual dimensions of security, and (iii) environmental displacement as potential concern for inclusive migration-security planning. By situating migration within the temporal, geopolitical, legal, and environmental transformations in South Asia, this chapter underscores how security regimes simultaneously construct, manage, and disrupt various mobilities. Rather than static threats or challenges, migration and security operate as dynamic, intersecting forces, revealing the contradictions embedded within regional governance structures. Addressing these paradoxes requires a departure from rigid, state-centric security paradigms toward a multiscalar, multilayered, historically grounded, and politically nuanced understanding of migration governance in South Asia.