Cover: Restraint and the Future of Warfare

Restraint and the Future of Warfare

The Changing Global Environment and Its Implications for the U.S. Air Force

Published May 11, 2020

by Bryan Frederick, Nathan Chandler


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Research Questions

  1. What are the major trends of concern in factors affecting the use of restraint in warfare?
  2. What results might arise from these trends?
  3. What are the implications for the U.S. Air Force and the future of warfare?

Military objectives often can be pursued using a number of different approaches: airpower versus ground forces, larger munitions versus smaller ones, more- or less-restrictive rules of engagement. Military effectiveness often favors the immediate application of overwhelming force, but militaries and their civilian overseers often opt for more-restrained approaches. Understanding how and why policymakers have chosen to impose these restraints in the past and how and why they are likely to do so in the future is critical to understanding how states will conduct future wars. This report identifies four key trends likely to shape the future exercise of restraint in warfare: the spread of lawfare (or use of law as a weapon of war), the widespread distribution of imagery of U.S. military operations, the increasing effectiveness of false accusations, and the increasing public concern for civilian casualties. These trends are assessed for how likely they are to affect both conflict between states and between states and nonstate actors, in addition to how the effects of these trends might differ for different types of states. Overall, these trends appear likely to further increase the incentives of decisionmakers in liberal democratic states to avoid civilian casualties in conflicts against weaker adversaries and to support investments in capabilities to make this possible. Other states that are more autocratic are not likely to be similarly constrained, and policymakers in democratic states will need to adapt to this asymmetry. Between highly capable state actors, conflict is less likely to occur but could involve very different incentives if operational considerations prompt a sharp reduction in the degree of restraint exercised beyond each state's legal obligations and the public shows a greater tolerance of heightened levels of military casualties and collateral damage to civilians. This report also provides specific recommendations for U.S. policymakers to begin to adapt to these anticipated trends.

Key Findings

Lawfare's significance is likely to increase

  • Future adversaries could be increasingly successful in developing tactics to use U.S. concern for the law of armed conflict to limit the utility of superior U.S. airpower, coerce restraint, and undermine support and legitimacy for U.S. military operations.

Widespread dissemination of warfare imagery could affect military decisions

  • Facing increased political risks, U.S. commanders might be deterred from undertaking some strikes in high-population environments, or they could decide to lengthen the review process for those strikes. Adversaries might respond by shifting their tactics and operating to a greater extent within population centers.
  • The potential for U.S. attacks to be documented in real time by civilians in information sources likely monitored by adversaries could increase the risk to U.S. forces undertaking the attacks or limit the effectiveness of those attacks.

False accusations of wrongdoing could become more effective

  • Concerns over the effectiveness of such information operations in Western countries have spiked since the unearthing of Russian efforts to interfere with the 2016 U.S. presidential election.
  • False accusations of misconduct or atrocities could affect U.S. domestic support for ongoing or future military operations. These risks are likely to be greater for operations that are conducted in higher-population areas (where such accusations would be more credible), and for operations that are conducted against relatively weak adversaries.

Trends in civilian casualty aversion, particularly in liberal democracies, could push for increasing restraint in warfare

  • If coalition partners become increasingly averse to the risk of civilian casualties, their utility to the United States in joint operations could decline, especially if they lack precision strike and sophisticated targeting capabilities.
  • Increasing civilian casualty sensitivity within the United States could lead Washington to be increasingly deterred from undertaking actions in certain contexts and environments.


  • Plan to deal with proxy forces: U.S. planning for operations should increasingly incorporate appropriate rules of engagement for encounters with groups that are operating as proxies of adversary states, both to limit the effectiveness of such groups and to limit the escalation risks they might pose.
  • Enhance focus on public affairs efforts: These capabilities are likely to become increasingly important to highlight adversary violations of the law of armed conflict. These capabilities also will be needed to rebut false accusations against U.S. forces and to maintain both domestic and international support for military operations. Greater professionalization and integration of public affairs officers with military operations should be explored.
  • Consider video recordings of U.S. operations: Although this would raise difficult legal, technical, and security concerns, policymakers should consider consistently making video recordings of U.S. operations and doing so in a manner that allows material to be released to the public if deemed necessary.
  • Prepare for more-limited utility of coalition partners: U.S. planning assumptions should incorporate the possibility that growing differences among coalition partners regarding acceptable risks of collateral damage could limit the ability of the United States to rely on partner support for future operations, particularly against nonstate groups and in urban environments.

Research conducted by

This research was sponsored by the United States Air Force and conducted by the Strategy and Doctrine Program within RAND Project AIR FORCE.

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