Question of Balance
Sheehan, Michael, Harvard International Review
Professor Wohlforth's article, ("Unipolar Stabilty: The Rules of Power Analysis," Spring 2007), is a thoughtful attempt to counter the suggestion that the "unipolar moment" identified by Charles Krauthammer has come to an end. This is an important point, particularly given the focus on polarity and balance of power associated with realism. It has triggered a long post-Cold War debate regarding the likelihood of balance re-emerging within the international system. Kenneth Waltz, in Theory of International Politics, insisted that the formation of balances of power is something of an iron law of international relations, perhaps the only one. A straightforward reading of realism therefore suggests that the present unipolar moment is an aberration and must, sooner or later, give way to a renewal of balance of power politics.
However, the historical record does not support this assertion. Unipolarity has been a frequent occurrence throughout history, and periods without balances of power are as common as balanced systems. When such balance of power systems have existed, they have frequently been followed by long periods of hegemony. Based on the historical record, there is every reason to believe that the period of American dominance may be a very long one. Where expansion of the system is difficult or impossible, hegemonies tend eventually to occur. In this regard the current global system is clearly a closed one, where expansion is not possible in the short or medium term.
Wohlforth is right to argue that American unipolarity is much more likely to endure than critics suggest. He is also correct in urging caution in terms of the assumptions and methodologies used to support the argument for emerging multipolarity. Thus the suggestion that China has already emerged is justly criticized by pointing both to the real weaknesses of China and the methodological problems associated with using purchasing power parity (PPP) as a measure of comparative economic muscle.
Nonetheless, Wohlforth's essay raises as many questions as it answers. Questioning the utility of using a primary indicator such as PPP as an economic measure raises the broader question of why "multipolarity" should be understood purely in adversarial military terms in the contemporary international system. …