Does Military Expenditure Worsen Environmental Degradation? A Systematic Literature Review

This study provides a systematic literature review (SLR) of the relationship between military expenditure and environmental degradation. Using the PRISMA framework and Scopus database, the study synthesises evidence from 74 quantitative studies across global, top defense-spending, and African contexts. The findings reveal a strong and consistent positive relationship between military expenditure and environmental degradation, measured through carbon emissions, greenhouse gases, and ecological footprint. Energy consumption emerges as the primary transmission channel linking militarization to environmental pressure. However, the relationship is not uniform. Evidence from developed and high military-spending countries indicates that technological innovation, renewable energy adoption, and institutional quality can mitigate environmental impacts. In contrast, African countries exhibit a more direct and less moderated relationship, reflecting structural and regulatory constraints. The study contributes to the literature by integrating the Environmental Kuznets Curve (EKC), Treadmill of Destruction (ToD), and Ecological Modernization Theory (EMT) into a unified analytical framework. Policy implications emphasize the need to incorporate environmental considerations into defense planning and promote sustainable military practices. The review also highlights gaps in causal identification, regional coverage, and theoretical integration, providing directions for future research.