Contested boundaries in changing climates: Precipitation variability and interstate diplomatic conflict

In this study, we examine how precipitation variability affects interstate conflict. As climate change worsens, extreme weather events and disasters become more frequent and intense, with growing impacts on human security and socioeconomic conditions. Reflecting concerns about how climate change influences interstate interactions, we argue that as the spatial variability of precipitation anomaly increases with more extreme water-related conditions, diplomatic interstate claims over territory and river are more likely to occur. Furthermore, we argue that precipitation anomalies specifically in border areas influence the chances for territorial and river claims between states. Our study finds that temporal precipitation anomalies increase the likelihood of territorial claim onsets while showing no significant effect on river claims. While country-level spatial variability of precipitation shows little impact on either type of claim, our analysis reveals border-specific effects: challenger states’ precipitation anomalies in border areas increase the likelihood of territorial claims, and spatial variability of precipitation in border areas marginally increases the likelihood of river claim onsets. In addition, countries with stable precipitation patterns in their border areas are more likely to be targeted for territorial claims. This research contributes to understanding the climate change–water–conflict nexus by examining how border-specific precipitation patterns influence interstate diplomatic conflict.