Global instability, the COVID-19 pandemic, recessionary shocks, and the full-scale Russian military aggression have intensified the vulnerability of national financial systems, transforming financial security into a cornerstone of state resilience. For Ukraine, the financial sector performs a dual function: it ensures economic continuity and forms a critical component of the broader national security environment. The collapse of traditional financial flows, disruptions in budgetary stability, and increased debt pressure have required the state to adopt new, scientifically justified approaches to financial sector management. Modern crisis conditions confirm that reactive responses are insufficient. Instead, states must rely on diagnostic and predictive mechanisms that support long-term financial sustainability and adaptability. The study presented in the file develops a methodological basis for modelling security processes in the financial sector to enhance proactive management under wartime and post-war transformation conditions.

The objective of the study is to form a scientific and methodological approach for constructing the state’s security environment through adaptive management of the financial sector. This includes transitioning from diagnostics of the financial security state toward forecasting and preventive regulation capable of strengthening national resilience.

The study applies a comprehensive methodological framework combining: (1) the calculation and interpretation of Ukraine’s Financial Security Index (FSI core) for 2020–2025; (2) correlation analysis to identify dominant sub-indices influencing financial stability; and (3) forecasting methods to project FSI dynamics for 2026–2028. An IDEF0 functional-modelling approach is used to visualize the management mechanism, including inputs (diagnostic data), controls (strategic documents), mechanisms (regulatory and statistical tools), and outputs (management decisions). This dual diagnostic–predictive methodology enables a shift from crisis response to anticipatory financial governance, supporting the formation of an integrated state security environment. The empirical results reveal a decline in Ukraine’s financial security beginning in 2021, a severe deterioration in 2022 due to escalation of war, and partial stabilization in 2024–2025. Forecasting for 2026–2028 shows gradual recovery, although pre-war stability levels remain unmet. Correlation analysis identifies debt security (r = 0.87) and budgetary security (r = 0.85) as the strongest determinants of the overall Financial Security Index, demonstrating that stabilizing the fiscal-debt block must become the key management priority. Other components—currency and monetary security—show moderate or weak effects, indicating structural imbalances that require targeted state intervention.The constructed IDEF0 model integrates diagnostic monitoring and predictive analytics, presenting financial sector security as a continuous, adaptive cycle. This model highlights that regulatory efficiency increases when real-time diagnostics are combined with scenario-based forecasting and legally supported management instruments.

As a result, the financial system is better prepared to withstand crisis shocks, enabling the state to transition from reactive stabilization to proactive resilience building. The study confirms that managing financial security in wartime and post-war reconstruction requires complex diagnostic and predictive tools. Budgetary discipline, debt sustainability, and strategic regulatory planning are central to strengthening the security environment. The diagnostic–adaptive model developed in the study creates a methodological foundation for proactive governance, enabling the state to anticipate risks, respond to external shocks, and reinforce institutional capacity.Future research should focus on developing integrated digital tools for real-time financial security monitoring, exploring cross-country comparison models for crisis-resilient financial governance, and adapting IDEF0 modelling for broader national security systems.

Additional studies should examine the impact of international financial support, reconstruction financing mechanisms, and the interaction between financial sector resilience and national defence capacity.