One of the leading scholars of IR theory is Joseph Nye, who teaches at Harvard University. He, along with co-author Robert Keohane, wrote one of the seminal works in IR theory–Power and Interdependence. Here is a short, but interesting TED talk in which Nye explains, amongst other things, the distinction between power transition and power diffusion, the “rise of China” and what “smart” power is.
Clouds, Clocks, and Sitting at Tables 