Overview
Since NATO’s 2014 Wales summit first codified a 2% of GDP defense spending guideline, Washington has pressed European allies to shoulder more of the continent’s defense burden. Under Donald Trump, that pressure has intensified from complaints about “free‑riding” to concrete demands for much higher spending, culminating in NATO’s 2025 Hague summit agreement to target 5% of GDP on defense and security by 2035 and, now, a U.S. push for Europeans to assume the majority of NATO’s conventional defense capabilities by 2027.
The December 2025 revelation that Pentagon officials have quietly told European diplomats Washington expects Europe to take over most of NATO’s conventional defense by 2027, with the implied threat of U.S. withdrawal from some NATO planning mechanisms if progress falls short, raises the stakes dramatically. It intersects with Russia’s ongoing war in Ukraine, EU initiatives like the SAFE loan program and Readiness 2030 roadmap, and sharp ideological friction between the Trump administration and EU institutions. Together, these dynamics are reshaping NATO from a U.S.-led shield into a more European‑centered military architecture, with uncertain implications for deterrence, alliance cohesion, and the future of U.S. power in Europe.
Key Indicators
People Involved
Organizations Involved
NATO is a 32‑member transatlantic military alliance founded in 1949 to provide collective defense under Article 5, which treats an attack on one as an attack on all. Long dominated militarily by the United States, the alliance is now grappling with how to adapt to Russia’s aggression, shifting global power balances, and U.S. domestic skepticism about overseas commitments.
The U.S. government has long been NATO’s dominant military power, providing the bulk of high‑end capabilities, logistics, and nuclear deterrence. Under the Trump administration, Washington has coupled support for NATO with explicit threats to reduce or condition U.S. involvement unless European allies dramatically increase defense spending and assume more operational responsibility.
The European Union, while distinct from NATO, has become a central player in efforts to strengthen Europe’s ability to defend itself. Through initiatives like the Readiness 2030 roadmap, SAFE defense loans, and coordinated procurement of key capabilities, the EU aims to close gaps in air and missile defense, drones, munitions, and strategic enablers.
SAFE is a €150 billion EU loan instrument designed to speed up European defense readiness by financing urgent and large‑scale joint procurement of priority military capabilities.
Timeline
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Senior U.S. diplomat attacks EU tech fine as harmful to transatlantic partnership
Public StatementU.S. Deputy Secretary of State Christopher Landau condemns a major EU fine against platform X, arguing that Europe cannot undermine U.S. tech companies while relying on U.S. security guarantees, highlighting broader tensions in the U.S.-EU relationship.
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U.S. sets 2027 deadline for Europe-led NATO conventional defense
Leak/ExclusiveReuters reports that in a meeting in Washington, Pentagon officials told European delegations that the United States expects European NATO members to assume the majority of the alliance’s conventional defense capabilities, from intelligence to missiles, by 2027. Officials suggest that if Europe falls short, Washington may withdraw from some NATO defense coordination mechanisms, though it is unclear whether this reflects formal administration policy.
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Trump administration National Security Strategy warns of Europe’s "civilisational erasure"
PolicyThe Trump administration releases a National Security Strategy that criticizes the EU as anti‑democratic, warns Europe risks "civilisational erasure," and questions whether future European societies will see their alliance with the U.S. the same way as NATO’s founders did, prompting European outcry.
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Putin warns Europe that Russia is ready for wider war
Public StatementRussian President Vladimir Putin warns that if Europe wants war, Russia is prepared and would defeat it decisively, while denying any plan to attack NATO members and accusing European powers of obstructing U.S.-led peace efforts on Ukraine.
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Canada joins EU SAFE initiative
Alliance/PartnershipCanada agrees to participate in the EU’s SAFE rearmament fund, becoming the first non‑EU country to join and underscoring both its desire to diversify away from U.S. defense dependence and the EU’s growing role in transatlantic defense financing.
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EU finalizes SAFE defense loan allocations
ImplementationThe EU allocates €150 billion in SAFE loans across 19 member states, with Poland and several eastern flank countries receiving the largest shares to strengthen their defense capabilities and industrial bases.
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Russia downplays impact of NATO 5% spending decision
ReactionRussian Foreign Minister Sergei Lavrov says NATO’s move to raise its defense spending target to 5% of GDP will not significantly affect Russia’s security, while criticizing the alliance for portraying Russia as a major threat.
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NATO Hague summit adopts 5% of GDP defense and security target
Alliance DecisionAt a summit in The Hague, NATO leaders agree to more than double the alliance’s defense and security spending target from 2% to 5% of GDP by 2035, with at least 3.5% devoted to core defense and the rest to resilience and critical infrastructure.
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Rutte says most NATO members back U.S. push to 5% defense spending
Public StatementAhead of the Hague summit, NATO Secretary General Mark Rutte reports that most allies support Trump’s demand for defense spending to reach 5% of GDP, combining 3.5% on core defense with 1.5% on broader security investments.
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Council of the EU adopts SAFE €150B defense loan instrument
PolicyEU member states approve the Security Action for Europe (SAFE) regulation, authorizing up to €150 billion in long‑maturity loans to support rapid, large‑scale defense investment through common procurement.
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EU unveils White Paper for European Defence and ReArm Europe / Readiness 2030
PolicyThe European Commission and High Representative present a White Paper and financing plan aimed at achieving EU "full defense readiness" by 2030, including measures to close gaps in air and missile defense, drones, ammunition, and strategic enablers.
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Washington NATO summit solidifies 2% as a minimum and signals higher ambitions
PolicyAllies at the Washington summit reaffirm that 2% of GDP should be treated as a floor, not a ceiling, for defense spending and acknowledge that higher levels will be needed to address Russia’s long‑term threat and other challenges.
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Trump says he would "encourage" Russia to act against under-spending NATO allies
Public StatementOn the 2024 campaign trail, Trump recounts telling a NATO ally he would encourage Russia to "do whatever the hell they want" to countries that are "delinquent" on defense spending, provoking condemnation from NATO officials and European leaders.
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Russia launches full-scale invasion of Ukraine
ConflictRussian forces mount a full‑scale invasion of Ukraine, triggering the deadliest conflict in Europe since World War II and prompting a surge in global and especially European defense spending, as NATO reinforces its eastern flank and reassesses force plans.
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Trump demands 4% of GDP defense spending at NATO summit
Public StatementAt a NATO summit in Brussels, U.S. President Donald Trump tells allies they should increase defense spending to 4% of GDP, doubling the existing 2% guideline and insisting that countries meet their obligations "immediately."
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Wales Summit launches NATO Defence Investment Pledge
PolicyNATO leaders agree at the Wales summit to aim to spend at least 2% of GDP on defense and 20% of defense budgets on major equipment within a decade, explicitly linking burden sharing to alliance cohesion after Russia’s annexation of Crimea.
Scenarios
Managed Europeanization of NATO Conventional Defense
Discussed by: NATO officials, Atlantic Council and other transatlantic think tanks, pro‑NATO European governments
In this scenario, European allies use the combination of NATO’s 5% spending target, the EU’s Readiness 2030 and SAFE programs, and national reforms to accelerate force build‑up and industrial capacity. By the late 2020s, Europe fields much larger, better equipped forces, closes key gaps in air and missile defense, munitions, and C4ISR, and assumes most day‑to‑day conventional defense tasks on the continent. The U.S. retains its nuclear umbrella, high‑end enablers and reinforcement capabilities, but reduces permanent ground presence and some planning roles. Alliance cohesion is maintained through careful coordination, and the 2027 deadline is informally treated as a milestone rather than a hard cutoff.
Tiered NATO and Partial U.S. Disengagement from Europe
Discussed by: Skeptical European analysts, some U.S. restraint advocates, parts of the European press
Here, European rearmament proceeds unevenly. Frontline states such as Poland, the Baltics, and some Nordics reach or exceed the 5% target and build robust forces, while larger economies like Germany, Italy, and Spain struggle politically to sustain rapid increases. The U.S. follows through on threats to step back from some NATO planning mechanisms and draws down select deployments, focusing more on the Indo‑Pacific and domestic priorities. NATO effectively becomes tiered: a core group of high‑spending European states capable of independent operations, and a peripheral group that remains heavily dependent on U.S. backing that is now less automatic. Deterrence holds but alliance politics become more fractious and regionalized.
Alliance Crisis and De Facto U.S. Exit from NATO Defense of Europe
Discussed by: Some European security commentators, critics of Trump’s NATO stance, Russian strategic thinkers (as a desired outcome)
In a darker scenario, continued rhetorical escalation from Washington, domestic U.S. political moves to restrict or condition NATO commitments, and slow European progress combine to produce a crisis. The U.S. may not formally leave NATO, but it could suspend or severely limit participation in key integrated commands, planning groups, and exercises, and publicly declare that under‑spending allies should not expect U.S. protection. European efforts to build independent capabilities lag behind, leaving a window in which Russia could test the alliance through coercion or hybrid attacks. Markets and publics react nervously, and some European states explore alternative security arrangements, including deeper EU defense integration or ad hoc coalitions.
Post-Trump Reset and Sustainable Transatlantic Bargain
Discussed by: Centrist U.S. and European policymakers, liberal think tanks, some business and defense industry voices
This scenario assumes a political shift in Washington after the 2028 U.S. election or a strategic recalibration within the Trump administration. High European defense spending and new capabilities are locked in, but U.S. rhetoric softens and Congress moves to codify aspects of NATO commitments. The 2027 deadline is quietly redefined as a benchmark rather than a rigid condition; the U.S. maintains a significant presence in European planning structures while expecting Europe to provide the majority of conventional forces and logistics. A renewed bargain emerges: Europe pays more and does more in defense, while the U.S. provides irreplaceable nuclear deterrence, high‑end capabilities, and political leadership in crises.
Acceleration of EU Strategic Autonomy and NATO Marginalization
Discussed by: Advocates of EU "strategic autonomy," some French and continental European strategists, a minority of U.S. skeptics of alliances
In this pathway, repeated clashes with the Trump administration over regulatory, trade, and values issues — combined with perceived unreliability of U.S. security guarantees — push EU institutions and key member states to prioritize autonomous European defense structures over NATO. SAFE, Readiness 2030, and defense industrial policies are oriented increasingly toward EU‑only frameworks; European forces train and plan more under EU banners and less through NATO. Over time, NATO’s integrated command structure atrophies, and practical defense planning shifts to EU‑led coalitions. The U.S. retains bilateral defense ties with select European partners but NATO itself becomes less central to European security.
Historical Context
The Mansfield Amendments and U.S. Troop-Withdrawal Threats in the 1970s
1966–1974What Happened
During the late 1960s and early 1970s, U.S. Senator Mike Mansfield repeatedly introduced amendments calling for substantial reductions of U.S. forces in Europe, arguing that wealthy allies should pay more for their own defense. While these efforts never fully succeeded, they reflected domestic pressure to reduce defense burdens and fueled transatlantic anxiety over U.S. commitments.
Outcome
Short term: The amendments were watered down or defeated, but they prompted consultations in NATO and spurred some European increases in defense spending and a modest rebalancing of costs.
Long term: The episode established a template for periodic U.S. threats to reduce its European presence as leverage for burden‑sharing, but the alliance ultimately remained intact and U.S. forces stayed in Europe.
Why It's Relevant
Today’s debate echoes the Mansfield era in its focus on domestic U.S. discontent with allied burden‑sharing, but the stakes may be higher: Trump’s rhetoric is more explicit about potentially denying protection, and Russia’s current capabilities and behavior present a more acute threat than in the détente period.
France’s Withdrawal from NATO’s Integrated Military Command
1966–2009 (partial withdrawal to full reintegration)What Happened
In 1966, President Charles de Gaulle pulled France out of NATO’s integrated military command, seeking strategic autonomy and control over French nuclear forces while remaining in the political alliance. France maintained bilateral defense ties and contributed to Western security but stayed outside many NATO military structures until it fully reintegrated in 2009.
Outcome
Short term: NATO adjusted its command structures to accommodate French withdrawal; U.S. and European forces continued to train and plan without French integration, though France cooperated in some operations.
Long term: Over decades, France participated increasingly in NATO missions and eventually rejoined the integrated command, demonstrating that partial decoupling did not spell the end of the alliance but did complicate planning and burden‑sharing.
Why It's Relevant
The French case illustrates that major allies can step back from parts of NATO’s military architecture without formally leaving the alliance. The current U.S. hints about withdrawing from some planning mechanisms if Europe misses the 2027 deadline could similarly produce a more fragmented but still existing NATO, rather than a clean break.
European Security and Defence Policy (ESDP) and Early EU Defense Autonomy Efforts
1998–2010What Happened
Following the 1998 St. Malo declaration between France and the UK, the EU developed the European Security and Defence Policy (later the Common Security and Defence Policy), creating EU‑led military operations and institutions intended to give Europe the capacity for autonomous action where NATO was not engaged.
Outcome
Short term: The EU launched several small‑scale missions in the Balkans, Africa, and elsewhere, but remained dependent on NATO for high‑end capabilities and struggled with capability shortfalls and political divisions.
Long term: ESDP/CSDP laid institutional groundwork for later EU defense initiatives but did not rival NATO as Europe’s primary security provider. NATO retained primacy for territorial defense and large‑scale operations.
Why It's Relevant
Earlier EU defense autonomy efforts show how slow and politically fraught it can be to build independent capabilities, even without acute external pressure. Today’s EU Readiness 2030 and SAFE initiatives operate at a far larger financial scale and in a far more threatening environment, but they may still face similar delays and coordination challenges as Europe races to meet both its own 2030 goals and the U.S. 2027 deadline.