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Summary
The world is experiencing unprecedented demographic change that could influence the likelihood of interstate war. As the global population grows, the old are concentrated in aging countries, while the young are concentrated in developing countries. A country with a youthful population can recruit more soldiers, pay less for them, and more easily motivate them to go to war. These factors diminish as populations age. Although this dynamic might lead to eventual peace, it also entails security challenges as Russia and China react to their shifting demographic profiles.
Deborah Jordan Brooks, Stephen G. Brooks, Brian D. Greenhill, and Mark L. Haas, “The Demographic Transition Theory of War: Why Young Societies Are Conflict Prone and Old Societies Are the Most Peaceful,” International Security, Vol. 43, No. 3 (Winter 2018/19), pp. 53–95, https://doi.org/10.1162/ISEC_a_00335.
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