The United States has launched a six-month review of its military forces stationed in Europe, amid growing tensions with some NATO allies over defense spending and operational support. The move was announced by U.S. Secretary of Defense Pete Hegseth during a meeting of NATO defense ministers in Brussels on June 18, ahead of the alliance’s upcoming summit in Ankara next month.

Hegseth sharply criticized several European allies for what he described as insufficient support for U.S. military operations against Iran, highlighting restrictions on the use of European bases for airstrikes. He called the refusal by some countries to grant access "shameful" and accused those governments of putting American personnel at unnecessary risk by denying predictable basing and overflight permissions. While the United Kingdom provided access to RAF Fairford in Gloucestershire for strikes on Iranian targets, many other European nations did not permit U.S. flights through their territories or the use of their airbases.

The review follows recent decisions to withdraw approximately 5,000 U.S. troops from Germany and to cancel the deployment of a long-range fire battalion there. These actions come amid strained relations between President Donald Trump and German Chancellor Friedrich Merz, as well as broader efforts by the Trump administration to encourage European NATO members to assume greater responsibility for their own conventional defense, particularly against Russian aggression.

Hegseth indicated that the continuation of U.S. troop presence in Europe will be contingent on NATO members meeting defense spending targets, expressing frustration with countries he described as underspending or “free riding.” He stated that “our annual NATO dues will be contingent on other countries meeting their defense spending targets” and warned that “NATO will be a two-way street.” The administration is reportedly pushing for NATO countries to eventually raise defense expenditures to 3.5% of GDP by 2035, surpassing the official guideline of 2%. Despite most members agreeing in principle, some European capitals—especially in the north and east—are expected to resist these demands.

Concerns have been raised about the potential impact of planned reductions in U.S. forces on NATO’s operational capabilities, particularly regarding maritime surveillance and deterrence against Russia. The review under consideration could involve withdrawing a significant portion of U.S. air assets and support aircraft assigned to NATO missions, which could affect the alliance's ability to maintain certain defense postures.

In his remarks, Hegseth also criticized European governments for focusing on social issues such as gender equality and climate change policies instead of prioritizing military readiness. He linked what he perceives as policy distractions to weakening European defense budgets and a perceived erosion of European unity and resolve.

The announcement was met with cautious responses from European officials who have called for close coordination with Washington to manage any troop reductions smoothly. NATO Secretary General Mark Rutte commented that Hegseth’s hard line “keeps the pressure on,” describing it as part of his role to maintain ally commitments.

Hegseth’s visit to Brussels was brief; he left before the close of the meeting, held shortly before Ukrainian President Volodymyr Zelensky addressed NATO allies seeking further military assistance. The review and discussions over defense spending and burden-sharing are expected to dominate NATO talks in Ankara, as the alliance seeks to balance transatlantic relations and collective security responsibilities amidst evolving geopolitical challenges.