Geopolitical expert Parag Khanna foresees a future where American influence is waning, and the new powerhouses (and threats) may not be the players you'd expect.

Political scientist Parag Khanna travels the world with his eyes open -- and has become a trenchant critic of the standard wisdom about the second and third worlds. Khanna's recent book, The Second World: How Emerging Powers Are Redefining Global Competition in the Twenty-first Century, looks at the epic political manipulations of nations struggling to end up at the top of the global heap. Esquire calls Khanna one of the 75 people who will influence the 21st century, precisely because it's these smaller countries that will shape the world's future.

Khanna argues that we're entering a time of apolarity -- when the traditional centers of gravity (US/Europe/Russia/China) will no longer hold. He sees a 21st century that has much in common with the feudal 16th century, where non-state actors have as much influence on the course of world events as countries do. His next book will explore this new medievalism and its effect on the diplomatic-industrial complex.