Trust represents a fundamental pillar of contemporary security policy, influencing decision-making processes, institutional stability, and the effectiveness of security measures at both national and international levels. This article explores trust as a key precondition for the formulation and implementation of security policy, emphasizing its role in relations between states, within security institutions, and between public authorities and society. The analysis focuses on trust as a multidimensional concept encompassing political legitimacy, transparency, accountability, and the credibility of security actors. Particular attention is paid to the consequences of declining trust, including increased social polarization, weakened resilience of democratic systems, and reduced effectiveness of collective security arrangements. The article argues that building and maintaining trust is not merely a normative objective, but a strategic necessity for ensuring long-term security and stability in an increasingly complex and uncertain security environment.Through comparative analysis of selected European states (Finland, Germany, Czech Republic, Poland, Hungary, France, and Estonia), the paper identifies critical determinants of trust, including transparency, institutional neutrality, crisis communication, and historical path-dependence. The findings demonstrate that trust acts as both an input to and an output of security policy, reinforcing legitimacy through reciprocity between citizens and the state.The article concludes that sustained trust-building must be recognized as a strategic dimension of security governance. Trust-based security strengthens societal resilience, mitigates polarization, and enhances adaptive capacity in hybrid threat environments.