India imposes an increasingly militarized border security agenda along its officially “friendly” border with Bangladesh with a range of preemptive practices to control the illegal movement of people and goods. Focusing ethnographic attention on everyday mobility, I view the articulations of national security in India's eastern borderlands through a gender lens to trace the logics of threat and protection that are made and unmade in everyday civil-military relations. The article explores the social and spatial forms through which civil-military relations unfold and proposes the idea of “security socialities” to think about these polychromatic relations between residents and security force personnel. Intimate yet fluid, ambivalent, and potentially violent, these instantiations of power show how border security is concretized and negotiated, stretched and challenged, but also made acceptable for a range of borderland residents. Security socialities point to the inextricable ties between everyday and spectacular violence of security projects and the relations that constitute them.