The state’s limited fiscal capacity amid increasing defense force development requirements calls for sustainable alternative financing sources. The Indonesian National Armed Forces (TNI) possesses state assets with strategic and economic value; however, their utilization remains suboptimal due to regulatory, governance, institutional, and stakeholder-coordination constraints. This study aims to analyze the factors affecting the optimization of TNI asset management, formulate an asset management model as a strategic defense-financing instrument, and develop policy recommendations to support national defense self-reliance. The study employs a mixed-methods approach with a sequential exploratory design. The qualitative phase uses in-depth interviews, observation, document analysis, and Focus Group Discussions (FGDs) with relevant stakeholders. Data are analyzed using NVivo, Soft Systems Methodology (SSM), SWOT, and Cost-Benefit Analysis (CBA) to identify problems and formulate a conceptual model. The model is then validated quantitatively using Structural Equation Modeling–Partial Least Squares (SEM-PLS). This study is expected to produce a TNI Asset Management Optimization Model integrating regulation, governance, institutions, partnerships, investment, and risk management within a sustainable defense-financing framework. The model is expected to improve the effectiveness of TNI asset utilization, strengthen independent defense financing, reduce dependence on the State Budget (APBN), and provide a basis for adaptive, accountable defense-asset management policies oriented toward strengthening the national defense posture.