Abstract
This article presents a comprehensive analysis of the transformation of the Armed Forces of the Republic of Lithuania in 1990–2025. The aim of the study is to identify the principal trends in the development of Lithuania's military system from the restoration of state independence to the present stage, taking into account personnel and structural changes. The theoretical framework of the study is based on the concept of military power as the sum of interrelated elements: the will of the army and society to resist and military concepts and organizational structure. These elements are further influenced by “force multipliers,” including political factors and allied commitments. The theoretical approach focuses on explaining long-term transformation processes; particular attention is paid to motivation, structural changes, and demographic constraints. The methodology combines general scientific methods (analysis, synthesis, and generalization) with specialized historical methods, applying a comparative approach within the broader Baltic regional context. In addition, quantitative data analysis is employed, particularly in assessing demographic indicators and changes in the personnel structure. The article also applies an institutional and organizational level of analysis, examining the evolution of the structure of brigades, battalions, and forces. In this way, the study combines a conceptual theoretical model and empirical data analysis in order to reveal the logic of the army's transformation over more than three decades. The source base consists of official statistical data, legal acts, and materials of the Ministry of National Defence of Lithuania. The scientific novelty of the study lies in its systematic interpretation of more than three decades of continuous transformation of the Lithuanian Armed Forces as an integral phenomenon, with particular attention to demographic constraints and the evolution of organizational structure. It is demonstrated that after 2014 the modernization processes acquired an accelerated character, with a particular emphasis on increasing firepower capabilities. The study concludes that the transformation of the Lithuanian Armed Forces in 1990–2025 took place under conditions of limited demographic resources, but with a gradual overall strengthening of militarization and integration into NATO's collective defence system.