How can we understand the audience agency and securitisation processes that can induce anxiety? The Copenhagen School of security studies conceptualises an audience as possessing political agency which is contingent on their capabilities to respond to securitising moves. Drawing on Anthony Giddens’s approach to ontological security, we argue that there is another type of agency supplementing political agency. Ontological agency refers to exercising control over the stability and continuity of one’s everyday routines and practices to minimise disruption to these routines caused by securitisation. Because routines of day-to-day life are central to bracketing sources of anxiety, people may choose to overlook and not react to securitising moves designating threats and implementing emergency measures that can undermine ontological security. We illustrate the analytical purchase of ontological agency by using unstructured observations of South Korean people’s responses to military practices that securitise North Korea. Our observations reveal that there is latent anxiety regarding North Korea that manifests in varying degrees ranging from inaction when routines are not disrupted by securitisation to outward bursts of emotional reactions and breakdown when securitisation practices disrupt people’s basic routines. This raises implications about the importance of ontological security driving the success or failure of securitisation and the politics of existentialism.