This revised report presents the key developments behind Trump Said He Was Considering Leaving NATO: What He Said, What the Law Allows and What Happened Next in a clearer structure, without adding claims beyond the original article.
US President Donald Trump said on 1 April 2026 that he was “absolutely” considering withdrawing the United States from NATO, escalating a dispute with European allies over the Iran war and the security of the Strait of Hormuz.
The statement was politically significant because the United States has been central to NATO since the alliance was founded in 1949.
It did not, however, mean the United States had already left the alliance or that withdrawal was legally or practically automatic.
By September 2026, the US remained a NATO member. Washington was reviewing troop deployments and reducing some military contributions in Europe, while also continuing infrastructure investment and new troop rotations in parts of NATO’s eastern flank.
That distinction between a threat, a policy review and actual treaty withdrawal is essential for understanding the story accurately.
What did Trump say on 1 April?
Trump told Reuters that he was considering pulling the United States out of NATO.
Asked directly whether withdrawal was under consideration, he responded that it was.
He also described himself as deeply dissatisfied with the alliance and had separately referred to NATO as a “paper tiger”.
The remarks followed several days of criticism aimed at European allies that had refused to support aspects of the US military campaign against Iran.
Why was the Strait of Hormuz part of a NATO dispute?
The immediate argument centred on Trump’s demand that allies do more to help reopen the Strait of Hormuz.
The waterway is a crucial global energy route, but it lies outside the traditional Euro-Atlantic area around which NATO’s collective-defence mission was designed.
France and other European governments argued that NATO was not created to conduct the kind of Hormuz operation Washington was seeking.
Trump, by contrast, argued that allies benefiting from US protection should support the United States when it faced a major security and economic crisis.
These were competing views about alliance responsibility rather than a simple dispute over whether Hormuz mattered.
What is NATO?
The North Atlantic Treaty Organization was created in 1949.
Its members include the United States, Canada and European countries.
The alliance was originally established in the early Cold War and has since developed a broad system of military planning, integrated command structures, exercises and collective defence.
NATO decisions are made by member governments rather than by a supranational government with authority over national armed forces.
What is Article 5?
Article 5 is NATO’s collective-defence commitment.
It states that an armed attack against one or more allies in the covered area is considered an attack against them all.
Each member then takes action it considers necessary, including the possible use of armed force.
Article 5 has been formally invoked only once, after the September 11, 2001 attacks on the United States.
Did Trump’s comments mean Article 5 had ended?
No.
The treaty remained in force for the United States unless and until the country completed a valid withdrawal process.
Political uncertainty can still weaken confidence in collective defence if allies doubt whether commitments would be honoured in a future crisis.
That is why Trump’s rhetoric mattered even without a formal withdrawal notice.
What does the NATO treaty say about leaving?
Article 13 of the North Atlantic Treaty allows a member to leave after providing notice.
The withdrawal becomes effective one year after the notice is given.
No NATO member has previously used Article 13 to leave the alliance.
This means even a legally valid US decision to withdraw would not normally make membership disappear immediately.
Can a US president leave NATO alone?
The answer is legally disputed.
The US Constitution explains how treaties are made but does not clearly set out how a president may terminate one.
Congress passed legislation in 2023 stating that a president cannot withdraw the United States from NATO without Senate approval or an act of Congress.
Reuters reported in April 2026 that the Trump administration maintained a broad view of presidential authority, while legal experts expected litigation if a president attempted to leave without congressional approval.
Because the Supreme Court has not definitively resolved this precise conflict between presidential and congressional authority, the legal outcome of a unilateral attempt would be uncertain.
What were European allies saying?
European leaders responded in different ways.
Poland’s defence minister urged calm and argued that the alliance remained mutually valuable to both Europe and the United States.
Germany reiterated its commitment to NATO.
Finland’s president told Trump that a more European NATO was emerging and that European members were taking greater responsibility for defence.
France stressed that NATO’s role concerned security in the Euro-Atlantic area and rejected the idea that the alliance was automatically responsible for a Strait of Hormuz operation.
Why Europe cannot instantly replace US capabilities
European NATO members have increased defence spending and military investment, but the United States supplies capabilities that cannot be replaced quickly.
These include strategic airlift, intelligence and surveillance, aerial refuelling, command systems, satellite support, long-range strike capabilities and nuclear deterrence.
Former US officials cited by Reuters said replacing the full range of American roles could take many years.
This is one reason the withdrawal debate matters even when European countries are spending more.
Why Trump had criticised NATO before 2026
Trump’s criticism of NATO predates the Iran war.
During both his first and second terms, he argued that European allies relied too heavily on the United States and did not spend enough on their own defence.
He repeatedly pushed members to meet or exceed alliance spending targets.
Supporters of that pressure say it encouraged Europe to invest more heavily in defence.
Critics argue that repeated doubts about US commitments can weaken deterrence by making potential adversaries uncertain about whether the alliance would respond collectively.
What changed after the April threat?
The US did not leave NATO.
Instead, the Trump administration began broader reviews of America’s military posture in Europe and pushed allies to assume more responsibility.
Some US force contributions were reduced or scheduled to decline.
In May, NATO’s top military commander said troop reductions would take place gradually over years rather than through an abrupt departure.
That approach gave European allies time to build additional capacity.
US military contributions were reduced in some areas
By June, the United States was asking European allies and Canada to provide more aircraft and naval assets for NATO defence plans.
US contributions of some fighter aircraft, drones, refuelling aircraft and ships were being reduced.
Those changes reflected Trump’s demand for greater European burden-sharing.
They still did not amount to US withdrawal from NATO.
What was the Pentagon reviewing by September?
In September 2026, the Pentagon was conducting a wider review of US military deployments in Europe.
The review considered different troop-level options and was linked to the administration’s push for Europe to take greater responsibility.
Congressional and diplomatic concerns remained significant because troop reductions could affect bilateral relationships and security along NATO’s eastern flank.
The final scale of any long-term drawdown remained under review.
Why later US actions complicated the “leaving NATO” narrative
Despite the withdrawal threats, the United States continued to invest in NATO-related infrastructure.
Reuters reported in September that Washington was still supporting critical infrastructure projects in Europe.
Trump also announced progress toward establishing a permanent US Army base in Poland.
And in late September, Lithuania said a new rotation of US troops was heading to the country.
These developments showed that US policy was not equivalent to a simple, immediate abandonment of NATO.
Why rhetoric still matters even without withdrawal
Military alliances rely partly on credibility.
Deterrence is strongest when a potential adversary believes allies will act together if one is attacked.
Repeated public doubts about collective defence can therefore have strategic effects even when treaty obligations remain formally unchanged.
European governments responded by increasing their own military capacity and, in some cases, diversifying procurement away from US suppliers.
Why Russia is part of the calculation
NATO’s eastern members view Russia as their primary military threat, particularly after Russia’s invasion of Ukraine.
Countries such as Poland and the Baltic states place high value on the presence of US forces.
Russia has denied hostile intentions toward NATO states, while Western governments have accused Moscow of cyber operations, sabotage and other forms of pressure.
The level of US involvement therefore affects how European countries assess deterrence and defence planning.
What would happen if the US actually left?
An actual US withdrawal would have consequences far beyond the removal of American troops.
NATO’s command structure, intelligence networks, logistics, nuclear arrangements and defence plans are deeply integrated with US capabilities.
Europe and Canada could continue an alliance without the United States, but they would need to replace or reorganise many capabilities.
The political consequences would also be significant because the alliance has long symbolised the US security commitment to Europe.
Would leaving NATO automatically remove all US forces from Europe?
Not necessarily.
US troops are stationed in European countries under a variety of bilateral and multilateral arrangements.
A change in NATO membership would raise major questions about those deployments, but individual governments could still negotiate separate basing and defence agreements with Washington.
Likewise, a reduction in troop numbers can occur without leaving NATO.
Readers should therefore avoid treating membership, troop deployments and bilateral alliances as the same legal issue.
What should readers understand as of September 2026?
The United States remains in NATO.
Trump’s April threat was genuine and politically important, but no completed withdrawal had occurred.
The administration had reduced some contributions, launched a Europe force review and demanded higher allied spending.
At the same time, US forces remained deployed across Europe and new rotations and infrastructure commitments continued in strategically important countries.
How to interpret future withdrawal headlines
Readers should look for a formal Article 13 notice, congressional action, court decisions and official NATO statements rather than assume that a political threat equals completed withdrawal.
Because the treaty provides for a one-year notice period, even a formal decision would create a lengthy transition.
Changes in troop levels should also be reported separately from treaty membership.
Conclusion
Donald Trump’s statement on 1 April 2026 that he was considering taking the United States out of NATO marked a serious escalation in tensions between Washington and European allies.
The dispute was fuelled by disagreements over the Iran war, the Strait of Hormuz and the broader question of how defence burdens should be shared.
But considering withdrawal was not the same as leaving.
US law creates significant congressional obstacles to unilateral withdrawal, the NATO treaty requires notice before departure, and as of September 2026 the United States remained a member while continuing military deployments and infrastructure activity in Europe.
The larger change has been a shift in expectations: European allies are being pushed to assume more responsibility while uncertainty about the long-term scale of US commitment has become a central issue in NATO planning.
Sources and further reading
See Reuters’ 1 April report on Trump’s NATO comments, NATO’s official North Atlantic Treaty and later Reuters reporting on US force reviews in Europe.
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