Dwindling water supplies are crucial to the military outcome in Iraq and Syria. Control of a dam means use of the water in its lake, use of the electricity it generates, and the chance to use the water to drown people downstream.

A multi-year drought caused the protests against Assad.

Global heating will eventually make it impossible for the current population of Iraq to survive there.

Our actions that cause global heating are a wrong that we must stop. Iraq contributes to these actions by extracting oil for us to burn. Iraqis also contribute to the problem by having more children than the region can support. One way of reducing population growth is to give women more control over their reproduction. ISIS will clearly do the opposite of that, but so do the religious Shi'ite groups.

Perhaps the world will need to adopt the principle that climate refugees must get sterilized as a condition for asylum. Not as a punishment (they are not personally to blame), but as a sustainability measure.