Internal wars in history: Triggered by natural disasters or socio-ecological catastrophes?

Abstract

Chaotic events that might be regarded as proximate causes in triggering war have rarely been considered in the large-N quantitative studies of historical warfare. Furthermore, it has not been fully determined which types of chaotic events, natural disasters or socio-ecological catastrophes, are more influential in modulating the likelihood of wars. This study is based on the incidents of 5368 natural disasters, 1478 famines, 5700 epidemics, 456 nomadic invasions, and 1315 internal wars in the agricultural region (including wheat and rice regions) of China in AD 1470–1911, together with Poisson regression and Granger Causality analyses, to explore the catalytic effect of natural disasters and socio-ecological catastrophes in modulating the likelihood of wars in history. The comparison between the wheat and the rice regions is focused. This is the first large-N inter-regional quantitative analysis on this topic. Our statistical results show that, in general, socio-ecological catastrophes are the proximate triggers of internal wars. Specifically, internal wars are triggered by epidemics in the wheat region, and they are ignited by famines in the rice region in historic China. In addition, internal wars in the two agro-ecological zones are revealed to be context-dependent. Also, conceptual models about the synergy of natural disasters and socio-ecological catastrophes in causing internal wars in the wheat and the rice regions are proposed, respectively. The above findings supplement the Malthusian theory by demonstrating the inter-connection among various mortality factors, which has rarely been examined empirically in academia. Moving beyond historic China, researchers are encouraged to boil down war data in other parts of the world by geographic regions in the course of their statistical analysis to examine each region individually in follow-up studies.