California’s ongoing drought is one sign that we have entered some uncharted and uncomfortable territory. Of the fears that have risen alongside a warming planet, perhaps none have attracted more attention than the “water wars” hypothesis.

This hypothesis says that increased water shortages around the world will lead to war between states. It goes something like this: as water is central to all human activities, including food production, no state can allow its water resources to be compromised. Therefore, in a world of squeezed water supply, states should be willing to go to war to protect their access to water. At its core, the “water wars” hypothesis expresses our deepest anxieties about a drought-laden future, wherein desperately thirsty societies take up arms against one another.