I emphasized how political and social interactions, including war, would be increasingly subject to the natural environment, which I labeled “the national-security issue” of the 21st century. Whereas the opinion pages of the time, both liberal and conservative, were obsessed with the clashing ideas shaping the post–Cold War world, I concentrated on how the increasing lack of underground water and the increasing lack of nutrients in overused soils would, in indirect ways, inflame already existent ethnic, religious, and tribal divides.
