The alliance that has defined Western security for nearly eight decades is now facing one of its most profound challenges. As the US-Israel war against Iran enters its second month, President Donald Trump is openly questioning the value of the North Atlantic Treaty Organization (NATO), threatening to pull the United States out of the bloc amid what he describes as a lack of support from European allies. The growing rift has left the transatlantic partnership shaken, with leaders on both sides of the Atlantic voicing frustration, caution, and, in some cases, outright defiance.
According to multiple reports, including interviews with The Telegraph and Reuters, President Trump described NATO as a "paper tiger" and said he is "absolutely" considering withdrawing the US from the alliance after the Iran conflict ends. "Oh yes, I would say [it's] beyond reconsideration. I was never swayed by NATO. I always knew they were a paper tiger, and Putin knows that too, by the way," Trump said in remarks published April 1, 2026.
The president's anger stems from what he sees as a lack of reciprocity. As the conflict with Iran has escalated, Trump has repeatedly called on NATO allies to provide military support—particularly in reopening the Strait of Hormuz, a vital maritime passage now largely under Iranian control. Yet, European leaders have balked at the request, citing both the dangers of direct confrontation and the conviction that this is not their war. German Defence Minister Boris Pistorius summed up the sentiment: "This is not our war. We have not started it."
Spain has led the opposition, closing its airspace to US military planes involved in the Iran conflict and denying the use of jointly operated military bases. Spanish Prime Minister Pedro Sanchez has described the war as "unjustifiable" and "dangerous." Italian officials, meanwhile, have denied US bombers the use of a military base in Sicily, though they left the door open to future requests on a case-by-case basis. The United Kingdom has permitted US bombers to use its bases, but only for defensive missions, not offensive operations against Iran. Prime Minister Keir Starmer made his stance clear, declaring, "This is not our war. We will not be drawn into the conflict. That is not in our national interest."
France, too, has refused to allow planes loaded with US military supplies destined for Israel to fly over its territory. Trump responded in characteristically blunt fashion, posting on Truth Social that France had been "VERY UNHELPFUL" and warning, "The U.S.A. will REMEMBER!!!" He also threatened to cut trade with Spain in retaliation for Madrid's refusal to cooperate.
Poland, which shares a border with Ukraine and has its own security concerns, announced it had "no plans" to relocate its Patriot air defense systems to the Middle East. "Poland’s security is an absolute priority," Defense Minister Wladyslaw Kosiniak-Kamysz wrote on X.
Efforts to form a multinational naval coalition to secure the Strait of Hormuz have been met with a chorus of refusals. Italy, the UK, France, Greece, and others have declined to participate, despite the fact that the closure of the strait has caused oil and gas prices to soar by up to 60 percent in some regions and disrupted global supply chains. Trump, for his part, has urged affected nations to "build up some delayed courage, go to the Strait, and just TAKE IT," as he posted on Truth Social. He also took a swipe at the UK's military capabilities, saying, "You don't even have a navy. You're too old and had aircraft carriers that didn't work."
The president’s rhetoric has not gone unnoticed. Secretary of State Marco Rubio echoed Trump’s frustrations, telling Al Jazeera that if NATO "is just about us defending Europe if they're attacked but then denying us basing rights when we need them, that's not a very good arrangement." Rubio, who co-sponsored a 2023 law requiring congressional approval for any US withdrawal from NATO, added, "All of that is going to have to be reexamined." White House spokesperson Anna Kelly reinforced the administration’s stance, saying, "President Trump has made his disappointment with NATO and other allies clear, and as the President has emphasized, 'the United States will remember.'"
European leaders, for their part, have defended their cautious approach. Prime Minister Starmer told reporters, "Whatever the pressure, whatever the noise, I am the British prime minister and I have to act in our national interests." He added, "I think it's in our interest to have a strong relationship with the U.S. and with Europe. But I do think that when it comes to defense and security, energy emissions and the economy, we need a stronger relationship with Europe." Starmer also stressed that NATO remains "the single most effective military alliance the world has ever seen."
Some, like Finnish President Alexander Stubb, have tried to strike a more conciliatory tone. "Constructive discussion and exchange of ideas on Nato, Ukraine and Iran. Problems are there to be solved, pragmatically," Stubb posted on X after speaking with Trump.
The strain is not just rhetorical. The USS Gerald R. Ford, the world’s largest aircraft carrier and a symbol of US naval power, is currently docked in Split, Croatia, for repairs after a non-combat fire during operations in the Red Sea. The ship’s presence in a NATO-allied port highlights the enduring, if tense, military cooperation between the US and its European partners. Yet, the broader picture is one of uncertainty. France’s Ministry of the Armed Forces revealed that Paris is in talks with about 35 countries for a future mission to reopen the Strait of Hormuz once the war ends, but the timeline and participants remain unclear.
Meanwhile, legal and political obstacles complicate any potential US withdrawal from NATO. While Trump has suggested he could pull out unilaterally, a Congressional Research Service report points out that a law passed in 2023 requires Senate approval or an act of Congress for such a move. Senator Thom Tillis, the top Republican on the bipartisan Senate NATO Observer Group, stated, "The president of the United States cannot withdraw from NATO. Now, having said that, the president can poison the well, the president can make it functionally defunct if he wants to."
For now, the alliance faces a moment of reckoning. Allies are weighing the costs of involvement in a war they did not choose against the risk of a fractured transatlantic security order. Shipping and trade experts warn that even if the Strait of Hormuz reopens tomorrow, the ripple effects on global supply chains will linger. As the world watches, the question remains: Can NATO weather this storm, or is the alliance that helped shape the modern era on the cusp of a historic rupture?
With leaders on both sides standing firm, the future of NATO—and the stability of the international order it underpins—hangs in the balance.