Donald Trump asked NATO for ships. NATO said no. Nine months later, the alliance that won the Cold War is negotiating the terms of its own irrelevance.The breaking point came in April, when European refusal to help reopen the Strait of Hormuz pushed Trump to call NATO a “paper tiger” and openly question why the United States stays in it at all. Tensions escalated further in April 2026, when European allies refused to support U.S. military operations against Iran, prompting Trump to describe NATO as a “paper tiger” and declare that U.S. commitment to the alliance was in question. That single sentence captures a rupture eight decades of alliance management had never quite produced.
What actually happened after February 28
Soon after the Israeli-U.S. war in Iran began on Feb. 28, 2026, U.S. President Donald Trump called upon NATO allies to help support the effort. The response of European leaders was at first mixed, with the United Kingdom offering limited backing while other members held back entirely. Some, like the United Kingdom, offered limited or qualified support. Others — chief among them Spain — refused to assist the U.S. at all.
That partial European response hardened into outright refusal once the war moved into its naval phase. NATO members’ opposition to getting involved with the conflict hardened further after the alliance decided to sit out the subsequent U.S. blockade of the Strait of Hormuz. For Washington, that was the moment political sympathy and operational commitment came apart.
“Virtually every NATO ally had privately agreed with the logic and legitimacy of striking Iran’s nuclear programme — yet none were willing to translate that agreement into action when asked to share the burden.”
That asymmetry, as one Brussels-based assessment noted, is precisely what infuriates Washington and what has now cracked the transatlantic facade wide open. Trump’s close ally Senator Lindsey Graham, after speaking with the president directly, described him as angrier than he had ever known him to be.
The Hormuz coalition that never formed
Washington’s attempt to assemble international naval cover for the strait failed almost immediately. Trump’s push to assemble an international force to police the Strait of Hormuz collapsed almost as soon as it began, prompting the president to turn his anger on the European allies who had declined to follow his lead. Pressed afterward on whether the US should leave the alliance, Trump stopped short of any definitive answer, but made clear he was deeply unhappy, adding that any exit decision would be his alone, with no congressional approval required.
Poland’s position illustrates the bind facing NATO’s eastern flank. Polish Foreign Minister Radosław Sikorski signalled a willingness to discuss the American request, framing it as a matter of respect for an indispensable ally. But the position was qualified from the outset: President Karol Nawrocki — who as commander in chief of the armed forces holds a decisive role on military deployments — had already made clear that Poland would not be sending forces to the Middle East. Central European states have the most to lose from US disengagement and the least appetite for a Middle East entanglement that has nothing to do with their own borders.
This is not the first crack this year
The Iran war compounded a transatlantic relationship already strained by Greenland. In January, long-standing Trump designs over Greenland seemed closer than ever, with the U.S. verbally, at least, suggesting it was prepared to use economic and military coercion to acquire the territory from Denmark, a NATO ally. The diplomatic crisis among NATO allies over Greenland in early 2026 has put the Alliance’s very cohesion at risk.
Denmark did not treat the threat as theater. Despite tensions having since subsided, Denmark has released unprecedented details about how it prepared to defend against military action by its longtime ally. That a NATO member felt compelled to publicly war-game defense against another member is itself a measure of how far trust eroded before Iran even began.
By the time Iran closed the strait in retaliation, the pattern repeated. Following Iran’s closure of the Strait of Hormuz in retaliation for the US and Israel military campaign, Trump threatened to withdraw the US from NATO out of discontent with the European allies’ refusal to send military vessels to reopen the strait by force.
Washington is already drawing down
The frustration has moved from rhetoric to force posture. The Trump administration plans to scale back the U.S. military forces that it would make available to NATO in a major crisis, three sources told Reuters, marking a significant shift in Washington’s commitment to the alliance. The move, expected to be communicated to allies at a defense meeting in Brussels, would reduce the pool of U.S. capabilities designated for rapid deployment under NATO’s force planning system.
Central to Trump’s argument is his belief that NATO allies have not supported the United States in moments of crisis, particularly during the recent war with Iran. He has accused member countries of failing when “tested” and, in stark terms relayed by the White House, argued that “NATO turned their backs on the American people” during the war.
The numbers behind the shift are large. The U.S. has long said it is looking at withdrawing a significant chunk of the roughly 80,000 American soldiers stationed in Europe, as Washington turns its gaze toward China’s growing power in the Indo-Pacific and contends with the strain of two and a half months of war in the Middle East. NATO’s Supreme Allied Commander framed the shift as evolution rather than retreat: “What we’re basically saying is, as the European pillar of the alliance gets stronger, this allows the U.S. to reduce its presence in Europe and limit itself to providing only those critical capabilities that allies cannot yet provide,” Supreme Allied Commander Europe General Alexus Grynkewich said in a press conference in Brussels.
Congress, for its part, is not unified behind a harder line. Last week, dozens of House Republicans voted for an amendment that would decrease funding for NATO by $481 million. The measure, which was rejected 333-80. The vote failed badly, but its existence signals where a faction of the governing party now stands.
NATO’s cohesion crisis in 2026 stems from European allies refusing to support US military operations against Iran, including a blockade of the Strait of Hormuz. Trump responded by threatening withdrawal and ordering a reduction in US forces designated for NATO’s rapid-deployment crisis response.
Why the alliance has survived worse than this
NATO scholarship offers a structural explanation for why, despite all this, formal withdrawal remains unlikely. NATO endures because its members, when forced to choose, have consistently decided that the alternative is worse. Contrary to the beliefs of those who see in every spat the potential end of the transatlantic relationship, the alliance is not held together by sentiment, shared values, or the memory of two world wars… It is held together by a calculation that the security costs of abandoning it exceed the political costs of sustaining it. That calculation has held through the many crises of the last eight decades; it is holding now.
A NATO-commissioned quantitative study backs the historical pattern, while complicating the simple “Russia threat unifies” narrative. This study uses a quantitative analysis to test key structural, economic, and political drivers of NATO cohesion between 1949 and 2023… The findings indicate the central role of trade interdependence in the cohesion of NATO. Surprisingly, higher tensions with Russia lead to decreased cohesion, suggesting divergent threat perceptions among members. That finding cuts against Washington’s working assumption that a hard external threat automatically produces alliance unity — it can do the opposite when members read the threat differently.
The damage that doesn’t reverse quickly
Even analysts confident the alliance survives this episode are blunt about what it costs. Trump’s threat to reconsider America’s NATO commitment may ultimately prove to be tactical leverage rather than genuine intent. But the underlying damage — to habits of consultation, to assumptions of shared purpose, to the basic expectation that allies inform one another before going to war — is real, and will not dissolve once the immediate crisis passes.
One European diplomat’s assessment, relayed anonymously, was unsentimental: trust, once broken, does not mend quickly, and the Hormuz standoff has deepened those fractures considerably. The alliance will survive this test. Whether it emerges from it with the same cohesion, the same credibility, and the same capacity for collective action is a question that will take years — not weeks — to answer.
This was not NATO’s first experience of European allies declining to follow a US lead outside its core treaty area. When Washington launched Operation Prosperity Guardian in December 2023 to secure Red Sea navigation, France, Spain, and Italy, three major European NATO members, declined to join the operation under U.S. command. The European Union subsequently launched a parallel mission, EUNAVFOR Aspides, in February 2024, which operates under a defensive mandate. The Iran war repeated that script at a much larger scale and with a much angrier American president.
NATO’s collective paralysis extended even to its own members under direct attack. When Iran struck Qatari LNG facilities in March 2026, cutting 17% of Qatar’s export capacity, NATO held discussions with Gulf partners, but produced no unified military response. Qatar is not a NATO member, but the episode underscored how little appetite the alliance has for collective action even adjacent to its traditional theater.
The nuclear backstop still holds, for now
Even as conventional force commitments shrink, Washington has been careful to ring-fence one element of the relationship. Pentagon Policy Chief Elbridge Colby has said the United States will continue to rely on its nuclear arsenal to protect NATO members, even as European allies take on greater responsibility for conventional forces. That distinction matters enormously to the math of deterrence: a NATO that loses tens of thousands of conventional troops but keeps the American nuclear umbrella is a fundamentally different alliance than one that loses both, and European capitals are treating the nuclear guarantee as the line that, if crossed, would mark a genuine rather than rhetorical rupture.
Colby’s own proposal for NATO’s future role has become a flashpoint inside the administration. Proposed by Elbridge Colby in February 2026, this plan wants NATO to go back to basics: focus only on defending Europe, not distant regions. It pushes higher defense budgets and burden-sharing. The logic is coherent on paper — a leaner, region-focused NATO with Europeans carrying more weight. But it collides with the same problem that produced the Hormuz refusal in the first place: Washington wants European help outside Europe, and Europeans want American commitment inside Europe, and 2026 has made clear that both sides increasingly doubt they will get what they want from the other.
The arithmetic of burden-sharing was already shifting
None of this happened in a vacuum. Trump’s demands for higher defense spending predate the Iran war by years, and the 2025 NATO summit produced a real, if contested, response. The Alliance agreed to commit 5% of GDP annually on spending by 2035 during the 2025 NATO Summit in The Hague, with 3.5% committed to core defense and 1.5% to broader defense- and security-related spending. Spain reportedly secured a partial exemption. That asterisk next to Spain’s commitment — the same country that refused any support during the Iran war — illustrates how burden-sharing disputes and operational disputes have become two faces of the same underlying argument about what allies owe each other and when.
The summit commitment was meant to settle the spending question for a decade. Instead, the Iran war reopened it within months, because Washington’s complaint was never really about percentages of GDP. It was about whether allies would show up operationally when asked, regardless of how their budgets looked on paper. A country can hit 5% of GDP and still decline to send a single ship to the Gulf, and 2026 demonstrated that this is exactly the scenario American policymakers fear most.
What happens next
Three things are now in motion simultaneously, and each will shape whether the cohesion debate cools or escalates further. The Brussels defense ministerial will formalize the scale of the US force drawdown, giving European capitals a concrete number rather than a rhetorical threat to plan against. European governments, having watched both Greenland and Hormuz unfold, are accelerating discussion of an independent European pillar that does not depend on Washington’s mood — though that pillar remains years from being able to substitute for the capabilities Washington is withdrawing. And the 2026 US House elections will test whether the America-first wing that pushed the failed NATO-defunding amendment gains ground or loses it — a result that will shape how much political room Trump has to follow through on withdrawal threats versus simply using them as leverage in future burden-sharing fights.
The alliance has absorbed bigger external shocks before: the end of its founding adversary in 1991, a chaotic withdrawal from Afghanistan, repeated disputes over Iraq. What it has not absorbed before is a sitting American president publicly weighing exit with no need for congressional sign-off, while simultaneously moving troops off the continent and ring-fencing only the nuclear guarantee as non-negotiable. Whether that combination proves to be tactical pressure or the start of an actual unwind is the open question for the rest of 2026.
FAQ
Why is NATO in a cohesion crisis in 2026?
European NATO members refused to support US military operations against Iran and declined to help reopen the Strait of Hormuz after Iran blockaded it. Trump responded by threatening to withdraw the US from NATO and ordering reductions in US forces designated for the alliance’s rapid-deployment crisis response.
Did any NATO members support the US war against Iran?
The response was mixed and limited. The United Kingdom offered qualified support, while Spain refused entirely. No NATO member contributed naval forces when Washington tried to assemble an international coalition to reopen the Strait of Hormuz.
Is the US actually pulling troops out of Europe?
The US has roughly 80,000 troops stationed in Europe and has signaled plans to withdraw a significant portion as it reduces the pool of forces designated for NATO’s crisis response system, shifting focus toward the Indo-Pacific.
Can the US president leave NATO without Congress approving it?
Trump has stated that a decision to withdraw from NATO would be his alone to make, without requiring congressional approval, though no formal withdrawal process was underway as of mid-2026.
Will NATO survive this crisis?
Most alliance scholarship suggests NATO will survive, since historically members have judged the cost of leaving higher than the cost of staying, even through serious disputes. But analysts caution that the damage to trust and habits of consultation will take years, not weeks, to repair.
