What is unipolarity like?

A series of general issues regarding the character of unipolarity have been debated thoroughly among scholars. These issues include: is unipolarity an adequate description, how durable is a unipolar system, should balancing still be considered operative, is the United States able to act in a benevolent way, and how strong is the United States actually?

Is unipolarity an adequate description of current world politics?

This debate addresses two dimensions, of which the one challenges the usefulness of polarity while the other accept the notion of polarity but challenges the adequacy of unipolarity. In the first place, some authors have questioned whether the concept of polarity still makes sense after the end of the Cold War. Instead, descriptions in terms of empire (Johnson; Hardt and Negri), first-among-equals (Heurlin) or moving towards apolarity (Ferguson), nonpolarity (Haass), have been suggested. In the second place, while accepting the notion of polarity, some authors have argued that multipolarity (Kupchank), moderated bipolarity (Waltz) or a mixture of uni- and multipolarity (Wæver) provides for a better description of current world politics.

How durable is unipolarity?

It is generally accepted that all international systems come to and end (Toft), but this debate regards the durability of unipolarity compared to other international systems such as bi- and multipolar systems.
Three positions have marked the debate on the durability of unipolarity. First, that unipolarity is a ‘brief moment’ by its very nature and thus should be considered a phase of transition (Waltz). Second, that it is durable because counterbalancing is inoperative (Brooks and Wohlforth). Third, that it is robust due to the lack of symmetrical great power balancing, but not necessarily durable as this depends on unit level factors (Hansen).

Balancing or not?

Kenneth Waltz has argued that unbalanced power is a momentary phenomenon only in international politics and that the U.S. therefore cannot escape counterbalancing. In contrast, Brooks and Wohlforth have argued that owing to the American preponderance of power, balancing has become inoperative.
In between these two positions, several authors have argued in favour of ‘soft’ or ‘issue specific’ balancing as replacing classic, ‘hard’ balancing (Paul; Pape). In addition, it has been argued that unipolarity per definition excludes symmetrical great power balancing but balancing still functions among the other states, and that asymmetrical restraint is posed in terms of free-riding strategies (Hansen).

Benign or malevolent?

As the sole superpower, will the United States be able to transcend balancing dynamics and become a benign hegemon by means of its policy? Kenneth Waltz has argued that the United States cannot avoid harming other states’ interest in spite of potentially good intentions. On the other hand, many authors have argued that the United States by means of a cooperative strategy and multilateral efforts is able to turn into a benign hegemon (Walt; Kupchank; Ikenberry).

How strong is the United States actually?

In contrast to the above issues, the question of American strength is mainly an empirical question, although also features of the unipolar system are considered to affect the U.S. position. Positions range from ‘U.S. decline’ to firm ‘preponderance of power’.
Advocates of U.S. decline (Haass; Ferguson) point to economic deficits and competition from China. Advocates of U.S. strength points to the superior U.S. capability score on several capabilities (Brooks and Wohlforth). Others, most notably Fareed Zakaria, have pointed to the diffusion of power to minor actors in spite of the continuous edge of U.S. strength.
The question of American strength is, indeed, a difficult one. As William Wohlforth has demonstrated in an analysis of the discrepancies between perceived, estimated and actual strength, it is always difficult to assess the strength of a state with precision. Furthermore, complacency is dangerous and it is important to scrutinize future trends as some of the advocates of U.S. decline have done. Finally, the coin has two sides of which only one regards the state of the American capabilities. The other regards the rise of rival powers.

Other issues

These general debates on unipolarity have prevailed in the literature. However, other debates have flourished, too. These regards the specifics of a functioning unipolar system and include questions regarding security strategies adopted, the role of nuclear weapons under unipolarity, the threat posed by international terrorism, and the importance of legitimacy.
Some debates of relevance to the unipolar world order have taken a broader scope or are still to come. Among the broader ranging debates within the realist paradigm, we could mention the debates on ‘what kind of realism’ and that on ‘international politics and foreign policy’
Since the end of the Cold War, classic realism has been subjected to a revival at the expense of neorealism as well as neorealism has developed into different interpretations.
Also the distinction between international politics and foreign policy, and the distinction between the market and the firms in the Waltzian perspective, has been challenged by several scholars.
These two developments are not specific to the theorizing of unipolarity, but may well be a consequence of the need for theoretical innovation produced by the end of the Cold War.
Regarding the analysis of the specific unipolar era, several dimensions still needs investigation and development, and several other debates are probably still to come, e.g., to what extent does the current world order affect relations between states?