2014, Ciccone 2011, Sarsons 2015), or that income gains due to rainfall may even increase the likelihood of inter-group conflict if it increases the ability of extractive rebel groups to finance fighting capacity (Eynde 2018).

From a political economy perspective, the relationship between water and fragility can be looked at through the framework of “greed” or “grievances” used to analyze natural-resource-based conflict (Collier and Hoeffler 2004, Dube and Vargas 2014). Income losses arising from rainfall shocks or disasters may give rise to grievances due to the pursuant economic hardships and thereby increase individuals’ willingness to engage in conflict. However, such negative shocks also lower “greed” for the spoils of war (or the “predation” motive) as the financial viability of engaging in conflict reduces. Integral to these channels is the interaction of inequality and sociopolitical institutions and how these mediate cooperation and conflict. Beyond income losses, shocks affecting food security may generate the same outcome, particularly in areas of subsistence agriculture where self-consumption of agricultural production is prevalent, as is the case in rural areas of Sub-Saharan Africa.

A complementary perspective relates to water availability (including through irrigation) changing the dynamics around the “quantity” and “distribution” of _lootable_ resources, and how complementary investment and policy reinforces those effects. Inequalities in resource endowments between different locations and population groups affects the likelihood of conflict breaking out (Berman et al 2017, Morelli and Rohner 2015). This suggests that the inequalities in water endowments can directly influence the onset and incidence of conflict. However, livelihood strategies and institutions have also evolved over the centuries to adapt to local ecological contexts (Dietz et al. 2003). Pastoralism, for instance, may be a strategy better-adapted to agroclimatic conditions that are not suitable for settled agriculture. The different property rights inherent in sedentary and pastoralist agriculture can then induce conflict over the control of land in regions settled by both types of farmers (Van Den Brink et al. 1995). Other evidence suggests that the presence of irrigation creates persistent inequalities in the productivity of agricultural land and can hinder cooperation and empower landed elites who may oppose democracy (Haber 2012, Jacoby and Mansuri 2018, Bentzen et al 2017).

Two recent works are closely related to our findings. McGuirk and Burke (2020) differentiate between two types of conflict: “factor conflict” for the control of territory and “output conflict” for the appropriation of surplus. Focusing on Africa, they exploit exogenous price variations to show that producers in cropproducing regions face an opportunity cost of engaging in conflict (or “soldiering”) which offsets the incentive to engage in factor conflict, but higher crop prices in areas without crop-production induce both types of conflicts. Additionally, McGuirk and Nunn (2020) show that climate-induced rainfall variation can induce conflict when they disturb the traditionally cooperative equilibrium between transhumant pastoral groups and sedentary agriculturists in Africa. Specifically, they show that droughts in grazing pastures give rise to conflict when they cause pastoral groups to infringe on agricultural lands before the harvest, leading to competition for scarce land and water resources. The evidence presented in our paper contributes to this recent literature on the proximate causes of conflict in Africa, by documenting how conflict dynamics are affected when regional instability spills over into a region like the Sahel, which hosts a large (non-cropproducing) population of pastoralists and where large-scale crop production is a recent phenomenon enabled by irrigation infrastructure, and thus is prone to conflict over the control of territory.

Finally, this brings us to the role of water sector infrastructure such as irrigation and dams. These investments are made to buffer against rainfall variability and disasters such as droughts and floods. Hence, they serve as important adaptation strategies to hedge against the threat of conflict breaking out by 4