Mowle Thomas S., Sacko David H. The Unipolar World: An Unbalanced Future

Palgrave Macmillan, 2007. — 215 p.The Unipolar World explains the international politics of the contemporary world. It completes structural realism by setting forth a theory of international politics when there is only one superpower. The authors distinguish between unipolarity and hegemony, and make analogy to the price leader model of microeconomics. Their research support realist predictions that a unipolar world will be relatively stable, and characterized by bandwagoning, flexible alliances, and resistance by the unipolar power to international law. When defensive power seems to have an advantage, the unipolar power will avoid involvement in international conflict, and unipolarity will be reinforced When offensive poser seems to have an advantage, the unipolar power will launch preventive wars, undermining its position in the international system.This book developed from Tom’s last book, Allies at Odds? The United States and the European Union. The comparative theory-testing of that book required a hypothesis for how structural realism would expect the United States and European Union to react to each other—and it quickly became clear that there was no such hypothesis. Allies at Odds began to develop what has become the second hypothesis of this book, that states would bandwagon with a unipolar power rather than balance against it.
This illustrated a more general problem in structural realism: its theorists had very little to say about a unipolar world. While Tom does not
consider himself a realist (though, after three major research projects that all ended up supporting the notion that states behave as if realist theory is valid, he recognizes that it is a pretty darn solid theory), it seemed to him that a decent theory ought to be able to talk about the world as it is, especially if it wants to call itself “realism.” Perhaps structural realism did not apply to a unipolar situation, but it seemed fair to at least put it to the test. Such a grand effort—to complete structural realism—seemed necessary but daunting.
Dave’s work involving the causes of war and international political economy pointed him to hegemonic stability theory. Right off the bat, his
tack was to disentangle hegemony from unipolarity and then think about the quantitative indicators he could thrust into the process. The next step was to turn our suspicions that structural realism was missing something from random musings into what we believe is solid piece of work. The most basic questions were also the hardest—explaining the difference between unipolarity and hegemony, answering the claim that balancing was central to realist theory, and developing the analogy to price leadership that extended Kenneth Waltz’s famous analogy of oligopolistic firms.
Knowing then that we were onto something, the small matter remained of developing hypotheses about the unipolar system and the behavior of states within it, and then of evaluating those theories. Working as we did on separate hypotheses, we were somewhat surprised as the book came together that our independent work spoke to and supported the rest of the book. Structural realism works in a unipolar world.