In his book "Earning the Rockies," Robert D. Kaplan discusses how America is evolving into a series of large urban centers that resemble city-states. These metropolitan areas are increasingly interconnected with global cities across other continents rather than with the rural and less populated areas within the country itself.

This phenomenon highlights a shift in America’s geographical and economic landscape, where urban hubs play a critical role in shaping its global position. The connections between these cities and their international counterparts may redefine how America interacts with the rest of the world, suggesting a more globalized future that emphasizes urbanization.