Nature and geopolitics can interact in nasty ways. The historian Geoffrey Parker has argued that changing weather patterns drove war, revolution and upheaval during a long global crisis in the 17th century. More recently, climate change has opened new trade routes, resources and rivalries in the Arctic. And now China, a great power that often appears bent on reordering the international system, is running out of water in ways that are likely to stoke conflict at home and abroad.
Natural resources have always been critical to economic and global power. In the 19th century, a small country — the U.K. — raced ahead of the pack because its abundant coal reserves allowed it to drive the Industrial Revolution. Britain was eventually surpassed by the U.S., which exploited its huge tracts of arable land, massive oil reserves and other resources to become an economic titan.