Roughly 80,000 U.S. troops in Europe could be redistributed under at least four force-posture options that the Pentagon plans to deliver to Defense Secretary Pete Hegseth by Nov. 6, according to a newly disclosed internal timetable. The options are expected to compare troop numbers, locations, the pace of any changes and their cost, making the review the clearest test yet of how the Trump administration intends to convert its demand for greater European responsibility into military deployments.
The six-month review was announced in June, but a Pentagon terms-of-reference document described by Reuters on Thursday adds concrete decision points. The top U.S. commander in Europe and Pentagon policy chief Elbridge Colby are due to hold a key options briefing by Sept. 18, followed by recommendations for Hegseth nearly a month before the review’s December deadline. Colby is also briefing NATO ambassadors in Brussels as allies seek clarity about whether Washington is considering modest adjustments or a broader reduction.
No withdrawal decision has been announced, and a review is not the same as an order to move forces. Yet the exercise matters because its scope extends beyond Army brigades and aircraft squadrons. The Pentagon is examining allied access, basing and overflight rights alongside the cyber, space and intelligence infrastructure that enables U.S. operations, tying the physical map of American forces to the less visible systems that make them effective.
A Review Built Around Multiple Military Variables
The review’s design suggests that the Pentagon is testing combinations rather than a single troop-cut target. A smaller force concentrated at highly permissive hubs could produce different military effects than the same number dispersed among more countries. Moving units quickly would also create different readiness and construction costs than a phased adjustment coordinated with allied procurement and force generation.
According to the Pentagon document, planners will assess whether allies offer dependable access, basing and overflight, commonly abbreviated ABO. A questionnaire sent to NATO governments asks about restrictions on U.S. access and whether countries would remove them, while also examining defense spending, procurement, strategy and support for American foreign-policy priorities. The Pentagon has framed the review as a consultation, and its official travel notice places Colby in Germany and Belgium for talks with allies.
That breadth makes the process more consequential than a conventional basing review. Airfields, ports, fuel storage, command networks and intelligence-sharing arrangements can determine how rapidly forces deploy and how long they remain effective. A country hosting few permanent U.S. troops may still provide essential transit rights or sensors, while a large garrison can be less useful if political restrictions limit operations during a crisis.
The Strategy Behind a Smaller American Role
The review follows the 2026 strategy, which says European allies should assume primary responsibility for conventional defense with “critical but more limited” U.S. support. That formulation does not call for abandoning NATO. It instead seeks to reserve scarce American capabilities for homeland defense and the Indo-Pacific while relying on European governments to supply more of the ground forces, ammunition, air defense and logistics required against Russia.
Colby described the review when it began as a way to move NATO “fast and irreversibly” toward that division of labor, according to Defense News. The distinction between burden-sharing and burden-shifting is central. Higher allied budgets can purchase capacity over time, but they do not instantly replace U.S. command-and-control, long-range transport, reconnaissance or integrated air defense. A credible transition therefore depends on the sequence of withdrawals and allied deliveries, not merely their announced totals.
The administration also appears to be treating military posture as leverage. The questionnaire asks whether allies have supported U.S. priorities outside Europe and whether they oppose measures that inhibit transatlantic defense-industrial cooperation. European officials told Reuters that linking basing decisions to broader political alignment can look transactional. The Pentagon’s counterargument is that access granted only after delays or subject to restrictions cannot be assumed in operational planning.
Europe Is Spending More, but Capability Takes Time
NATO members committed at the 2025 Hague summit to spend 5 percent of gross domestic product on defense and related security needs by 2035. Under the formal commitment, at least 3.5 percent is meant for core military requirements, with the remainder available for infrastructure, resilience and other security investments. Annual plans are supposed to demonstrate a credible path toward the target.
The trajectory is upward but uneven. NATO said European allies and Canada increased core defense expenditure by nearly 20 percent in 2025, while only five allies were expected to meet the 3.5 percent core benchmark in 2026. Seventeen were projected to reach the separate 1.5 percent guideline for broader security investment, according to the alliance’s July spending update. Those figures show acceleration, not completion.
Money also measures input rather than deployable output. NATO’s force model aims to keep more than 300,000 troops at high readiness, backed by air and naval power, but readiness requires trained formations, equipment, stocks, transport and compatible command systems. The Pentagon’s terms of reference therefore ask whether allies are filling gaps in NATO crisis forces, a more operational test than whether a finance ministry crossed a percentage threshold.
Congress Has Built Guardrails Around Troop Cuts
The executive branch does not have a completely free hand. The fiscal 2026 defense authorization law prevents the Pentagon from keeping U.S. troop levels in Europe below 76,000 for more than 45 days until Hegseth and the commander of U.S. European Command certify that the change serves U.S. national security and that NATO allies were consulted. The provision also requires an assessment of the consequences, according to the Senate sponsor’s summary.
With the current force described as roughly 80,000, that statutory floor leaves room for reductions without triggering the certification process, but not for an unrestricted long-term drawdown. It also does not prevent relocations within Europe, changes in unit mix or reductions in capabilities assigned to NATO plans. The legal constraint is therefore important but narrower than the full operational question confronting the review.
Congressional scrutiny is likely to focus on whether the Pentagon measures military effect rather than simply personnel. The Government Accountability Office found that the European Deterrence Initiative strengthened posture through rotational deployments, exercises, pre-positioned equipment and construction, but said the department needed clearer performance goals and measures. That GAO finding is relevant to any new plan: troop counts alone do not show whether deterrence, reinforcement capacity or alliance readiness has improved.
The Decision Will Turn on Sequencing
The most consequential choice may be the pace at which responsibilities shift. A gradual approach could tie U.S. adjustments to verified European milestones, such as combat-ready brigades, air-defense units, ammunition stocks and assured access. A faster reduction could create stronger incentives for allies to act, but it could also produce temporary gaps if budgets have not yet become fielded capability.
The Pentagon will also have to decide which American assets are genuinely replaceable. European armies can expand conventional formations, but some U.S. contributions provide alliance-wide leverage far beyond their personnel totals. Intelligence networks, space support, theater logistics, air refueling and senior command structures connect national forces into a functioning defense plan. Retaining those enablers while reducing other units would represent a different military posture from an across-the-board cut.
By Nov. 6, Hegseth is expected to receive a spectrum of choices rather than a predetermined answer. What the new timetable establishes is that the administration’s burden-sharing campaign has entered detailed force planning, with allies being judged on operational access and usable capability as well as spending. What remains unresolved is how much risk Washington is prepared to accept during the transition, and whether European forces can assume new missions before U.S. capacity is removed.
