Tactical Defeat, Structural Victory:A VDI–GRI Reassessment of the Imphal Operation and Its Contribution to Indian Independence

Conventional war studies have long equated tactical outcomes with historical outcomes, resulting in a narrow interpretation of victory and defeat. This study challenges that assumption by introducing two quantitative models: the Victory–Defeat Index (VDI), which evaluates political, social, and civilizational structures of war, and Gain-Return Index (GRI), which measures the purpose, means, legitimacy, and social impact of military action. Applying these models to the Imphal Operation (1944), we demonstrate that the operation—traditionally viewed as a tactical defeat for the Japanese Army—constitutes a structural victory for the Japan–INA coalition and the Indian independence movement. VDI reveals high structural legitimacy and long‑term political impact for the Japan–INA coalition, while GRI distinguishes the liberation‑oriented actions of Japan–INA from the extractive colonial actions of the British Indian Army. The integrated VDI–GRI framework clarifies how tactical defeat can transform into historical victory, offering a new analytical paradigm for war evaluation beyond battlefield outcomes. This study contributes to structural war analysis, colonial studies, and independence movement research, and provides a generalizable model for future comparative studies across different theaters and civilizations.