Three grand strategies appear to be influencing the second Trump administration. These strategies have different implications for key dimensions of U.S. policy toward Europe. How might the alternatives affect European allies’ alignment with the United States, defense spending, and security cooperation with each other?

How Might NATO Allies Respond if the United States Retrenches from Europe?

Miranda Priebe, Zachary Burdette, Scott Behmer

ResearchPublished Oct 8, 2025

The second Trump administration has signaled that it plans further changes to U.S. policy toward Europe, including withdrawing some military forces from the region. But the administration has not settled on an overarching strategy. As it weighs options, the United States should consider many factors, including how to prioritize threats across theaters and how policy changes would influence the behavior of Russia and China. One key dimension of this broader calculation—and the focus of this report—is how NATO allies might respond.

Three grand strategies appear to be influencing the administration: Global Primacy, Prioritize Asia, and Prioritize the Western Hemisphere. Each strategy has different implications for U.S. commitment to NATO allies, military posture in Europe, economic relations with NATO allies, and policy toward Russia. Drawing on existing international relations literature and RAND research on the effects of U.S. retrenchment during the Cold War, the authors offer a preliminary assessment of how alternative policies might affect European allies’ alignment with the United States, defense spending, and security cooperation with each other.

Key Findings

  • No single logic appears to be guiding the United States’ approach to Europe, so U.S. policies might work at cross-purposes from the perspective of the three competing grand strategies.
  • Sustaining high tariffs to reduce the U.S. trade deficit with Europe could drag on allies’ economies, and, in turn, constrain their defense spending.
  • A rapid U.S. military drawdown in Europe might spur more allied defense spending and cooperation than a gradual withdrawal but would risk immediate capability gaps and suboptimal defense investments.
  • Using U.S. commitments and military presence to reward and punish individual allies would risk incentivizing allies to focus on national rather than collective defense. Some allies might try to hold on to any security ties with the United States by taking such steps as buying U.S. equipment or conducting bilateral military planning and exercising with the United States, even if such steps are not optimal for strengthening European military capacity for collective defense.
  • Some allies might reduce intelligence-sharing and security cooperation with the United States if the United States pursues a détente with Russia that does not prioritize peace in Ukraine or European stability more generally.

Recommendations

  • If the administration seeks to promote European security cooperation as the United States retrenches, the administration should avoid using the remaining U.S. commitment and troop levels to reward and punish individual allies. Instead, any changes in U.S. commitments should apply to NATO as a whole and posture changes should be driven by an assessment of defense needs within Europe and across theaters, such as the Indo-Pacific.
  • If higher allied defense spending is a priority, consider alternatives to high tariffs for reducing the trade deficit. The United States could, for example, negotiate to mutually reduce tariff and non-tariff barriers to decrease the U.S. trade deficit with Europe without undermining allies’ economies and their willingness to spend on defense.
  • If sustaining European allies’ strong alignment with the United States is a priority, the United States should condition any U.S.-Russia détente on concessions from Russia on European security.

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Priebe, Miranda, Zachary Burdette, and Scott Behmer, How Might NATO Allies Respond if the United States Retrenches from Europe? Santa Monica, CA: RAND Corporation, 2025. https://www.rand.org/pubs/research_reports/RRA2807-2.html.
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Funding for this research was made possible by generous gifts from the Stand Together Trust and from Peter Richards, a longtime RAND supporter and member of the RAND Global and Emerging Risks advisory board. This work was conducted by the RAND Center for Analysis of U.S. Grand Strategy, an initiative of the International Security and Defense Policy Center of the RAND National Security Research Division.

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