Compulsory text: Samuel Huntington (1999): The Lonely Superpower.

Huntington argues that "the global structure of power in the Cold War was basically bipolar; the emerging structure is very different. There is now only one superpower. But that does not mean that the world is unipolar. A unipolar system would have one superpower, no significant major powers, and many minor powers. As a result, the superpower could effectively resolve important international issues alone, and no combination of other states would have the power to prevent it from doing so. For several centuries the classical world under Rome, and at times East Asia under China, approximated this model. A bipolar system like the Cold War has two superpowers, and the relations between them are central to international politics. Each superpower dominates a coalition of allied states and competes with the other superpower for influence among nonaligned countries. A multi polar system has several major powers...".