This article investigates the demographic consequences of major wars and the determinants of post-war demographic recovery, analyzing severe conflicts from 1914 to 2010 in countries across various development levels and war types. Through an empirical evaluation of demographic recovery following major wars, this paper explores how several important factors, including political capacity, foreign aid, and human capital, influence recovery patterns in societies that have experienced these conflicts. The analysis suggests that populations tend to recover to pre-war levels within a generation, often exceeding them due to significant post-war baby booms. Political capacity appears to be associated with faster recovery, while the impact of foreign aid and human capital varies across different economic contexts. The research employs a large N time-series cross-section analysis, offering a comprehensive exploration of the dynamics involved in post-war demographic recovery. The results highlight the complex relationship between political, economic, and social factors, providing a valuable foundation for future research. By integrating insights from political demography, international relations, and population studies, these findings can guide the development of new theories and models to better understand the mechanisms of post-conflict recovery. Ultimately, this research aims to inform more effective strategies and policies for post-conflict reconstruction and development, promoting sustainable peace and stability in war-affected regions.