Polarity in international relations is any of the various ways in which power is distributed within the international system. It describes the nature of the international system at any given period of time. One generally distinguishes three types of systems: unipolarity, bipolarity, and multipolarity for four or more centers of power. The type of system is completely dependent on the distribution of power and influence of states in a region or globally.
It is widely believed amongst theorists in international relations that the post-Cold War international system is unipolar: The United States’ defense spending is “close to half of global military expenditures; a blue-water navy superior to all others combined; a chance at a powerful nuclear first strike over its erstwhile foe, Russia; a defense research and development budget that is 80 percent of the total defense expenditures of its most obvious future competitor, China; and unmatched global power-projection capabilities.”
Unipolarity in international politics is a distribution of power in which one state exercises most of the cultural, economic, and military influence.
- Unipolarity is an interstate system and not an empire. Monteiro cites Robert Jervis of Columbia University to support his claim, who argues that “unipolarity implies the existence of many juridically equal nation-states, something that an empire denies.” Monteiro illustrates this point further through Daniel Nexon and Thomas Wright, who state that “in empires, inter-societal divide-and-rule practices replace interstate balance-of-power dynamics.”
- Unipolarity is anarchical. Anarchy results from the incomplete power preponderance of the unipole. Columbia University’s Kenneth Waltz, whom Monteiro cites, argues that a great power cannot “exert a positive control everywhere in the world.” Therefore, relatively weaker countries have the freedom to pursue policy preferences independent of the unipole. The power projection limitations of the unipole is a distinguishing characteristic between unipolar and hegemonic systems.
- Unipolar systems possess only one great power and face no competition. If a competitor emerges, the international system is no longer unipolar. In 1964, Kenneth Waltz maintained that the United States is the only “pole” to possess global interests.