A tale of two worlds: core and periphery in the post-cold war era

As the world moves away from the familiar bipolar cold war era, many international relations theorists have renewed an old debate about which is more stable: a world with two great powers or a world with many great powers. Based on the chief assumptions of structural realism—namely, that the international system is characterized by anarchy and that states are unitary actors seeking to survive in this anarchic system—some security analysts are predicting that a world of several great powers will lead to a return to the shifting alliances and instabilities of the multipolar era that existed prior to World War II. For instance, John Mearsheimer argues that “prediction[s] of peace in a multipolar Europe [are] flawed.” Thomas Christensen and Jack Snyder argue that states in a multipolar world can follow either the pre-World War I or the pre-World War II alliance pattern, thus implying that a third course is improbable. They further assert that “the fundamental, invariant structural feature, international anarchy, generally selects and socializes states to form balancing alignments in order to survive in the face of threats from aggressive competitors.” The realist argument predicts that great powers in a self-help international system will balance one another through arms races and alliance formations.