Forecasting the level of conflict two decades ahead is not something we political scientists are very good at – in part because we lack appropriate theories and in part because it is hard to tell how the world will look in the future. The 2030 report appears to use a combination of projecting current trends and relying on some key indicators such as demographics to predict declining or no conflict between great powers, states in general, and within states, subject to some reservations about the possible impact of climate deterioration, resource scarcities, ascending powers, and new weapons.
I would probably make a similar but not identical projection based on different theoretical premises. My forecast would be based on arguments developed in The Arc of War (University of Chicago Press, 2011), an examination of the evolution of warfare since its initial appearance and co-authored with Jack S. Levy. Levy and Thompson make six general arguments. The first one is about the origins of war and need not concern us here. The other five do appear to be germane.
- War co-evolves with other activities, including military and political organization, political economy, threat environment, and weaponry.
- Major changes in politico-economic complexity, in particular have led to occasional transformations in warfare. Yet, the expansion of warfare is not inexorable. An important constraint in the escalation of warfare are its costs which have influenced strongly and negatively the probability of warfare between industrialized states in the contemporary era.
- The pace of change/transformations in warfare has significantly accelerated three times – first in the late fourth to early third millennium BCE, then in the last half of the first millennium BCE, and again in the second half of the second millennium CE.
- The attempt to centralize regional political-military power is one of the major drivers of periods of acceleration and transformation, especially in the third acceleration, which was concentrated in the Western trajectory.
- Much of the world did not experience the third acceleration directly (other than as targets) and remains more agrarian than industrial. As a consequence, states outside of the western trajectory tend to be weaker, vulnerable to internal warfare, and prone to fight fewer and shorter interstate wars.
Thus, warfare between industrialized major powers should continue to be regarded as too costly and therefore not very likely in the next few decades. Interstate warfare should also continue to be infrequent mainly because most states lack the resources to engage in it for very long. But we would expect intrastate warfare to continue more or less at current levels because so many states are vulnerable to coercive challenges at the domestic level. Since drought and oil/water shortages seem likely and most likely to occur in places that are least able to cope with such problems, anticipating limited interstate warfare may prove to be optimistic. But the increased problems caused by climate and scarcities may at least tell us which parts of the world are most likely to experience conflict in the near future.
William R. Thompson is Distinguished Professor and Donald A. Rogers Professor of Political Science at Indiana University, Bloomington. He also is Managing Editor of International Studies Quarterly. Recent books include Asian Rivalries: Conflict, Escalation, and Limitations on Two-Level Games, Handbook of International Rivalries, 1494-2010, and The Arc of War: Origins, Escalation and Transformation. Forthcoming next year are How Rivalries End and Transition Scenarios: China and the United States in the Twenty-first Century.