Strategic rivalries are contests between states that view one another as threatening competitors and treat each other as enemies. A disproportionate amount of interstate conflict is generated by a relatively small number of these pairs of states engaged in rivalries that can persist for years. Thus, to understand interstate peace and conflict, it is useful to know how rivalries work in general and more specifically. In the past two decades, a strenuous effort has been mounted to introduce the concept of rivalry and demonstrate its utility in unraveling conflict situations. Yet all rivalries are not exactly alike. We need to move to a more rewarding differentiation of how they differ in general. Principal rivalries are those antagonisms that are most significant to the decision makers in a state. The main distinction on issues about which rivals dispute are positional and spatial concerns. Positional rivalries contend over regional and global influence. Spatial rivals contend over which state deserves to control disputed territory. Interventionary rivalries predominate in sub-Saharan Africa. Their primary focus involves neighboring states attempting to influence who rules and how co-ethnics are treated. This book updates the inventory of strategic rivalries from 1816 to 2020. Principal rivalries are identified for the first time and cover the same period. A theory stressing the two main types of rivalry (positional and spatial) is elaborated and tested. Regional variations on the origins and terminations of spatial rivalry are explored and interpreted. In addition, attention is paid to fluctuations in the intensity of positional rivalries by examining the working of the contemporary major power triangle (United States, Soviet Union/Russia, and China) and, more generally, the dynamics of regional power that are rising in terms of their relative capability and status in the system. Variations in cooperation and termination dynamics both in general and according to rivalry type are also examined. Overall, the emphases of the book are split between demonstrating the utility of distinguishing among rivalry types and examining selected rivalry dynamics.

The three main levels of analysis in international relations have been the systemic, the national, and the individual. A fourth level that falls between the systemic and the national is the region. It is woefully underdeveloped in comparison to the attention afforded the other three. Yet regions tend to be distinctive theaters for international politics. Otherwise, we would not recognize that Middle Eastern interstate politics somehow does not resemble Latin American interstate politics or interstate politics in Southern Africa (although once the Middle East and Southern Africa may have seemed more similar in their mutual fixation with opposition to domestic policies in Israel and South Africa, respectively). This book, divided into three parts, first makes a case for studying regional politics even though it must also be appreciated that regional boundaries are also hazy and not always easy to pin down empirically. The second part examines power distributions within regions as an important entry point to studying regional similarities and differences. Two emphases are stressed. One is that regional power assessments need to be conditioned by controlling for weak states which are more common in some regions than they are in others. The other emphasis is on regional power hierarchies. Some regions have strong regional hierarchies while others do not. Regions with strong hierarchies operate much differently from those without them in the sense that the former are more pacific than the latter. The third part of the book focuses on regional differences in terms of conflict behavior, order preferences, rivalries, and rivalry termination.