Jihad over Centuries

TL;DR

This paper explores how historical decline of trans-Saharan cities in West Africa fostered Islamist insurgencies, highlighting the role of water access, military asymmetries, and ideological transmission in the persistence of radical Islamism.

Contribution

It introduces a novel historical and empirical analysis linking ancient water sources and military dynamics to modern Islamist violence patterns.

Findings

Violent hotspots correlate with historical city decline and water source loss.

Military asymmetries led to outward submission, enabling radical survival.

Ideological transmission persists through religious practices and is supported by a dynamic conflict model.

Abstract

This paper investigates the origins of Islamist insurgencies as a form of cultural revival in West Africa. Exploiting variation in access to ancient water sources, which have largely disappeared, as an instrument, we show that the decline of trans-Saharan cities -- once-prosperous under pre-colonial Islamic states -- led to contemporary hotspots of Islamist violence. Contemporary violence is concentrated not where colonial resistance by Islamic states was fiercest, but where overwhelming military asymmetries induced outward submission, a pattern supported by historical evidence on weapon access. This strategic adaptation allowed radical Islamism to survive defeat and persist as a latent legacy. Qualitative evidence suggests ideological transmission was sustained through a religious practice of internally preparing to reassert Islamic purity. This mechanism is further supported by a dynamic model of conflict and individual-level surveys examining extreme religious ideologies. Moreover, the concentration of Islamist violence in areas that experienced reversals of fortune mirrors a global pattern.