Volgy, Thomas J., Kelly Marie Gordell, Paul Bezerra, and Jon Patrick Rhamey, Jr. "Conflict, Regions, and Regional Hierarchies." Oxford Research Encyclopedia of Politics 2017.-06-28. Oxford University Press.  

Available online here.

Abstract: Despite decades of scholarly attention to conflict and cooperation processes in international politics, rigorous, comparative, large-N analyses of these questions at the region level are difficult to find in the literature. Turning attention to a region level unit of analysis does not require abandoning decades of scholarship at the state or dyad levels. Indeed, much of this work may be viewed as informing or complementary to comparative regional analyses. In particular, regional propensity for cooperation or conflict is likely to be conditioned by a number of prominent explanations of these phenomena at state and dyad levels, which may usefully be conceived in their regional aggregates as so-called regional fault lines or baseline conditions. These include the presence of major and/or regional powers, interstate rivalries, unresolved territorial claims, civil wars, regime similarity, trade relationships, and common membership in intergovernmental organizations. 

Of these baseline conditions, the impact of major and regional powers on regional patterns of cooperation and conflict is notable for both its theoretical and practical implications. Power transition theory, hegemonic stability theory, hierarchical theory, and long cycle theory all suggest major—and to a lesser extent regional—powers will seek to establish order within areas under their influence; alternatively, the overwhelming capabilities these states bring to a region arguably act as a deterrent inhibiting conflict. Empirical analysis reveals—irrespective of the causal mechanism at hand—regions characterized by the presence of a major or regional power experience less conflict. Moving forward, future research should work to test the two plausible causal mechanisms for this finding—order building versus deterrence—to determine the true nature of hierarchy’s pacifying influence. 

Keywords: regions, conflict, hierarchy, MIDs, major powers, regional powers, cooperation, empirical international relations theory