| This dissertation asks three interrelated questions on unipolarity: Is it peaceful? Is it durable? And, how does it impact deterrence? Each of the three chapters below lays out a theory that provides an original answer to each of these questions.;Chapter One addresses the question of whether unipolarity is peaceful. My argument shows there is no good reason to expect unipolarity to foster peace. The chapter lays out a theory of conflict in unipolarity, showing how a world with a sole great power produces incentives for conflict. Neither the structure of a unipolar world nor U.S. strategic choices have a clear beneficial impact on the overall prospects for peace. A unipole can implement one of three types of grand strategy. First, a strategy of dominance will focus on minor powers, which do not possess the capability to deter the unipole. Threatened by the latter, recalcitrant minor powers will try to increase their relative power (e.g., by developing nuclear weapons). But, before they do, the unipole is likely to attack them. Second, a strategy of defense of the status quo will produce not dampen uncertainty about the unipole's intentions, similarly prompting minor powers to bolster their deterrent capability. Such revision of the status quo is, however, likely to be opposed by the unipole; and war is, once again, likely to ensue. Finally, a strategy of disengagement, though eliminating tensions vis-a-vis the unipole, leaves other regions of the globe on their own, making room for wars among other states. In the case of unipolar regions, conflict will result from the dynamics described above. In case of bipolar and multipolar regions, conflict is likely to result from the several mechanisms described by theories about such structures. In sum, for the world as a whole, unipolarity makes conflict likely. For the unipole itself, it presents a difficult choice between disengagement and frequent conflict. In any case, unipolarity hardly allows for the peaceful conversion of the unipole's power into favorable outcomes.;Chapter Two addresses the impact of unipolarity on deterrence. In this chapter, I argue that the perception that deterrence is less relevant in a unipolar world is wrongheaded---and has significant policy implications, namely a penchant for a more liberal use of force in preemptive and preventive ways by the unipolar power. The problem lies in the failure of extant scholarship (and, consequently, of policymakers) to capture an essential aspect of deterrence---assurances. Though acknowledged since the outset of deterrence theory as a core aspect of deterrence, assurances were placed in the background by the balance of power that existed during the Cold War. After showing how threats and assurances work hand-in-hand to bolster the success of deterrence, I extract implications for two important areas. First, I explore the sources of credibility in power and reputation. Second, I show how my argument relates to different system polarities, requiring states to focus on threats (balanced power; bipolarity and multipolarity) or assurances (unbalanced power; unipolarity).;Finally, Chapter Three deals with the question of whether unipolarity is durable. I begin by establishing the logical separation between balancing and a systemic balance of power. Then, I establish how, in a nuclear world, the goals of balancing---guaranteeing state survival---can be successfully achieved under conditions of unipolarity short of pursuing a reestablishment of a systemic balance of power. Unipolarity is therefore potentially durable. The key to its durability in practice, however, depends on the grand strategy implemented by the unipole. A unipole bent on domination will lead other states to pursue balancing strategies that will erode its power preponderance and eventually put an end to unipolarity. A disengaged unipole will open the space for regional competition among states, leading to regional balancing efforts that may also eradicate its power advantage and bring about a systemic balance of power. But a unipole that defends the status quo provides no security-driven incentives for other states to balance beyond the acquisition of survivable nuclear arsenals, creating the conditions for perpetuating its position. Besides yielding more specific empirical implications than alternative theories, this contingent view on the durability of unipolarity is consistent with the empirical record, since none of today's medium powers has thus far engaged in a push to end U.S. power preponderance. (Abstract shortened by UMI.)... |
