As geopolitical tensions persist into late 2025, debates over the United States’ role in the North Atlantic Treaty Organization (NATO) continue to intensify. Calls for a potential US withdrawal have sparked discussions about the alliance’s future, while NATO leadership emphasizes the indispensable transatlantic partnership.
The Legal Process for US Withdrawal from NATO
The foundation for any NATO member’s withdrawal, including the United States, is outlined in the North Atlantic Treaty signed in 1949. According to Article 13 of the treaty, after the agreement has been in force for 20 years, any member country can withdraw by providing a one-year notice of denunciation. For the US, this notice would be deposited with the US government itself, as it serves as the treaty’s depository.
However, the process isn’t solely a presidential decision. In 2023, Congress passed legislation requiring congressional approval for any unilateral presidential withdrawal from NATO, mandating either a two-thirds Senate vote or an act of Congress. This measure was designed to prevent abrupt exits and ensure broader oversight. Legal experts note that while the president holds authority over treaty withdrawals under the Constitution, this law adds a layer of complexity, potentially leading to court challenges if ignored.
In practice, initiating withdrawal would involve the president issuing a formal notice, followed by a 12-month period during which the US would still be bound by NATO obligations, including Article 5’s collective defense clause. During this time, diplomatic negotiations and adjustments to alliance structures could occur. Notably, no country has ever fully withdrawn from NATO, though France temporarily left the military command structure in 1966 before rejoining in 2009.
Political Moves and Debates Surrounding US Exit
As of 2025, political momentum for a US NATO withdrawal has intensified. In December 2025, a US congressman introduced the NATO Withdrawal Act (H.R. 6508), which proposes a formal notification to exit the alliance within 30 days, bypassing traditional timelines. This bill reflects growing isolationist sentiments in certain political circles, amplified by earlier executive actions. For instance, in February 2025, an executive order withdrew the US from several international organizations, signaling a broader retreat from multilateral commitments, though NATO was not directly targeted.
Debates have also linked NATO withdrawal to other strategic interests, such as access to Greenland for military purposes. Proponents argue that leaving NATO could allow the US to pursue independent deals, while critics warn of diminished global influence. These discussions are set against a backdrop of calls for Europe to assume more defense responsibilities, with some viewing US involvement as an outdated burden.
Reasons Why Some Advocate for the US to Leave NATO
Advocates for a US exit from NATO cite several key reasons, rooted in economic, strategic, and ideological concerns. Primarily, there’s the financial burden: The US contributes approximately 74% of NATO’s total defense spending, which some argue unfairly subsidizes European security at the expense of American taxpayers. This disparity has fueled calls to redirect resources toward domestic priorities like infrastructure or border security.
Strategically, critics view NATO as a relic of the Cold War, originally designed to counter the Soviet Union, which no longer exists. They argue that continued membership entangles the US in European conflicts, potentially drawing it into unnecessary wars under Article 5. In 2025, isolationist policies have gained traction, with some leaders expressing disdain for the alliance and pushing for a focus on Asia-Pacific threats like China instead of Europe.
Additionally, proponents believe withdrawing would force European nations to build stronger independent defenses, fostering self-reliance and reducing US overcommitment. This perspective aligns with broader anti-globalist views, seeing NATO as a tool that diminishes US sovereignty.
Why NATO Cannot Easily Sustain Without the US Military
NATO’s structure and effectiveness are deeply intertwined with US military capabilities, making sustainability without American forces a significant challenge. The US provides the bulk of the alliance’s military might, including advanced intelligence, logistics, and command structures. Without the US, NATO would lose critical assets like airborne warning and control systems (AWACS), extensive joint training programs, and a substantial portion of its rapid deployment forces.
Economically, the 23 EU countries in NATO represent only about a quarter of the alliance’s total output, underscoring the US’s dominant role. The US nuclear umbrella is another irreplaceable element, offering deterrence against threats like Russia, which intelligence assessments suggest could pose risks as early as 2027. Europe’s defense industry remains fragmented, hindering the development of autonomous capabilities to match current NATO standards.
Geopolitically, shared interests such as defending the Arctic and North Atlantic require US involvement, as European allies alone cannot adequately counter activities from powers like Russia and China in these regions. NATO leaders have emphasized that transatlantic unity is essential for collective security, warning that separation could embolden adversaries. While Europe has over a million troops and modern weaponry, the loss of US leadership would diminish NATO’s overall edge, potentially leading to a weaker deterrence posture.
Efforts to boost European spending, such as Germany’s pledge to reach 3.5% of GDP on defense by 2029, are steps forward, but they are framed as complementary to US involvement, not replacements.
Implications of a Potential US Withdrawal from NATO
A US exit would have profound ripple effects. For NATO, it could trigger a reevaluation of the alliance, possibly leading to a more EU-centric defense framework, though calls for such independence have been rejected in favor of continued collaboration. Geopolitical stability in Europe might falter, with increased vulnerability to external threats. For the US, withdrawal could reduce military expenditures but at the cost of influence in Europe and access to strategic bases.
Globally, it might encourage other alliances or shifts in power dynamics, affecting ongoing conflicts like those in Ukraine. Experts warn that such a move could be as destabilizing as major security threats.
Balancing Independence and Alliance in a Changing World
The prospect of the US withdrawing from NATO raises fundamental questions about global security architecture. While the legal pathway exists, political hurdles and strategic dependencies make it a contentious endeavor. Advocates push for reduced burdens, but the alliance’s reliance on US military prowess highlights the risks of separation. As debates evolve in 2025, maintaining transatlantic bonds remains key to deterring threats and ensuring collective defense.
