Cover: Measuring Power, Power Cycles, and the Risk of Great-Power War in the 21st Century

Measuring Power, Power Cycles, and the Risk of Great-Power War in the 21st Century

Published Apr 15, 2020

by Jacob L. Heim, Benjamin M. Miller


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Research Questions

  1. How should policymakers measure the balance of power?
  2. What kinds of shocks affect which nations have the most power?
  3. How can modeling compare assumptions about which states are gaining or losing power?
  4. How can policymakers use a model to predict when shifts in the balance of relative or perceived power portend conflict?

There is growing concern that U.S. power has been declining relative to the growing power of Russia and China. This concern renews long-standing questions about how we should measure national power, which nations have the most power, which states are gaining and losing power, and when such shifts in relative or perceived power might portend conflict. The authors explore these questions, illustrating a quantitative, scenario-based approach for policymakers who are interested in measuring the interstate balance of power, assessing the impact of shocks on the balance of power, and identifying periods during which shifts in the balance of power could portend conflict between major powers. The methodology demonstrates how different climate change scenarios, population projections, or economic growth forecasts lead to different balances of global power, then uses power cycle theory to map those changes in the distribution of global power to changes in the risk of conflict between major global powers. The authors demonstrate the potential of this methodology using three illustrative examples. They find that global power can be "sticky," meaning it takes drastic assumptions about the future to create meaningful changes in the global balance of power. Further, because their model treats global power as a relative concept, the authors find that the types of shocks that affect the risk of conflict are the types that create relative "winners" and "losers."

Key Findings

The balance of power can be sticky

  • • Different assumptions did not result in drastically different forecasts of the balance of power. Thinking in this manner can help policymakers focus on truly game-changing problems rather than day-to-day crises. That said, "sticky" does not mean "immutable."

Not all shocks are equal

  • • The types of shocks that matter for determining the balance of power are the types that create "winners" and "losers."

The authors' methodology enables comparison of different assumptions

  • • The authors' framework is versatile but does not assess risks of great-power conflict that are unrelated to the balance of power.

The believability of the outputs depends on the believability of the inputs

  • • Models such as the one presented in this report can provide a common ground for comparing alternative assumptions.

Research conducted by

Funding for this report was provided by gifts from RAND supporters and income from operations. The research was conducted within the RAND Center for Global Risk and Security.

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