Download Free Electronic Document

FormatFile SizeNotes
PDF file 0.1 MB

Use Adobe Acrobat Reader version 10 or higher for the best experience.

Research Brief

Key Findings

  • Large-scale first strikes like Operation Iraqi Freedom will likely remain rare.
  • Emphasis on striking first does not require a major shift in planning.
  • A first-strike strategy requires outstanding strategic intelligence.
  • U.S. first-strike strategy may have unintended consequences.

When national leaders recast U.S. national security policy following the terrorist attacks of September 11, 2001, they announced that, in the future, the United States would take advantage of opportunities to strike at potential adversaries before they attack. This doctrine of "preemption" actually includes two elements. True preemptive attack occurs when a country strikes an enemy to foil or mitigate the effects of an imminent attack against it (such as when Israel struck Egyptian airfields at the beginning of the Six Day War in 1967). Preventive attack, which is historically more common, involves striking an enemy to avert an apparently inevitable threat from materializing in the longer term (such as the 2003 invasion of Iraq). Because the enemy's future intentions are rarely certain, preventive attacks are difficult to justify as being necessary for self-defense—yet not acting to prevent a potentially catastrophic threat may appear unacceptably dangerous. Although U.S. leaders occasionally considered striking adversaries first before 2001, they rarely carried out such attacks, and had never done so on such a scale before Operation Iraqi Freedom (OIF).

How likely is the United States to carry out first strikes in the future? What are the implications of this policy for U.S. military capabilities and planning? RAND Project AIR FORCE (PAF) studied the potential role of striking first in the contemporary security environment, drawing on historical cases in which countries have either contemplated or carried out first strikes. Researchers drew the following conclusions:

  • Large-scale first strikes like OIF are likely to remain infrequent. The United States is more likely to consider first strikes than it was before the recent policy shift, but the factors that have discouraged such attacks in the past continue to apply. Many threats are difficult to anticipate, and even when opportunities exist to strike first, the potential military advantages are usually small compared to the anticipated political costs at home and abroad. The failure of intelligence regarding Iraq's weapon programs and the costs of the continuing insurgency there will also make similar operations seem less palatable in the future.
  • The strategic emphasis on striking first does not require a major shift in U.S. defense planning. Even when the United States chooses to strike first, the military requirements will be case-specific. The forces needed to strike potential state adversaries would vary widely, and each would be very different from those needed to strike nonstate terrorist groups. In each case, the military capabilities required would be largely the same whether the United States struck first or second. If anything, military requirements tend to be less demanding in a first-strike scenario because the United States would have the advantage of dictating the terms of the fight.
  • A first-strike strategy requires outstanding strategic intelligence. Although any military strategy suffers if intelligence about the enemy is deficient, preemptive and preventive attacks are especially dependent on understanding the enemy's intentions and capabilities. The difficulty of gathering such intelligence and making accurate predictions can be reduced but not eliminated. The U.S. Air Force's traditional focus on strategic attack should place the service in the forefront of thinking about how to gather and analyze such information more effectively.
  • U.S. first-strike strategy may have unintended consequences. States or other actors expecting to be attacked by the United States may perceive powerful incentives to strike first; dangerous though it is to start a war with the world's only superpower, allowing the United States to attack on its own terms is likely to be seen by such actors as an even worse alternative. The United States can discourage such threats by designing forces, basing architectures, and deployment schemes that minimize the U.S. military's vulnerability to preemptive attacks by its adversaries.

These conclusions suggest that the new emphasis on striking first in U.S. national security policy since September 11, 2001, is not likely to produce a correspondingly great change in the shape or use of American military power in the future.

Research conducted by

This report is part of the RAND research brief series. RAND research briefs present policy-oriented summaries of individual published, peer-reviewed documents or of a body of published work.

This document and trademark(s) contained herein are protected by law. This representation of RAND intellectual property is provided for noncommercial use only. Unauthorized posting of this publication online is prohibited; linking directly to this product page is encouraged. Permission is required from RAND to reproduce, or reuse in another form, any of its research documents for commercial purposes. For information on reprint and reuse permissions, please visit

RAND is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.