Health security has become a central pillar of modern health systems, particularly in light of the growing transboundary health threats and the challenges revealed by the COVID-19 pandemic, which exposed the fragility of many health systems—especially in fragile and conflict-affected states characterized by displacement, irregular migration, and weak health infrastructures. This study aims to analyze the concept of health security, clarify its objectives and domains, and review its measurement indicators, while highlighting its role as a strategic entry point for achieving Universal Health Coverage (UHC), with a particular focus on the Libyan context. The study adopts a descriptive–analytical approach based on a review of scientific literature and international reports issued over the past decade, including those published by the World Health Organization, the World Bank, and the Global Health Security Index. The findings indicate that achieving Universal Health Coverage without strengthening the foundations of health security remains a fragile accomplishment. Conversely, integrating health security into national health policies represents a strategic option for enhancing health system resilience and ensuring the sustainability of health services, especially in countries with institutional fragility. The study recommends adopting an integrated and participatory approach to strengthening health security in Libya as a pathway toward achieving Universal Health Coverage. It also proposes an evaluative framework for health security indicators and applies it to the Libyan context, identifying key challenges and offering practical policy recommendations. Keywords: Health security; Universal Health Coverage; health systems; health policies; fragile states; Libya.