What’s your big idea?

The big idea is that geography explains why the West rules the world—and why its domination may not last much longer.

There are two sides to the story.

First, geography determines how societies develop. The world’s first complex societies appeared toward the Western end of the Old World (around 9000 BC), because, thanks to geography, more plants and animals that could be domesticated had evolved there than anywhere else on earth. Geography dictated that East Asia had fewer potentially domesticable plants and animals.

The second part of the story, however, is that social development determines what geography means. When societies developed to the point that it could organize irrigation systems (about 4000 BC), that changed geography’s meaning. Having access to great rivers now became all-important. Egypt and Mesopotamia turned into breadbaskets.

By about 500 BC, though, societies had developed far enough to master the sea. Greece’s and Rome’s access to the Mediterranean mattered more than access to great rivers.

By AD 1500, sailors could cross the Atlantic—but not the Pacific, which is twice as wide. The result: Europeans discovered and colonized the Americas. By 1800, Europe had had an industrial revolution and could project power globally.

By 1900, societies could master the Pacific too, drawing East Asia into the global economy. North America, with access to both oceans, soon replaced Europe at this economy’s core.

By 2000, social development had shrunk the Pacific. East Asia is moving from being a periphery to being a new core in its own right.

What geography gives, it can also take away....