Since the full-scale Russian invasion of Ukraine in 2022, Sweden has witnessed a substantial build-up of both military and civil defense. With this development, cultural heritage has been assigned a new role in war preparedness. This article addresses the question of what makes cultural heritage an appealing and productive national security asset in an established democracy. Focusing on the under-researched issue of heritage's domestic security role, the article explores the role and meanings ascribed to cultural heritage in contemporary security policies and war preparedness initiatives. The specific aim is to investigate how heritage is framed as a vital national security resource. What values are projected onto the past, and what security functions are attributed to cultural heritage? The study combines critical heritage studies (CHS) with feminist and critical international relations (IR) theories on security and militarization. Through a framing analysis highlighting central metaphors, the article demonstrates that heritage is ascribed a dual meaning: both as a national treasure that needs masculinized protection, and as a resource that strengthens defense willingness and enhances deterrence capabilities. The article argues that cultural heritage becomes a particularly productive security resource due to its capacity to activate a logic of threat. Moreover, the emotional force and gendered dimensions of heritage help depoliticize issues of security, potentially constraining critical discussions on rearmament and militarization.