Donald Trump’s NATO allies are increasing resistance to getting involved in his Iran war, risking a deeper rupture in the already strained military bloc.

Spain closed its airspace to U.S. jets Monday, and Italy denied U.S. military aircraft bound for the Middle East permission to land at a base in Sicily, according to a person familiar with the matter. Poland said it has no plans to relocate its Patriot batteries, following a report that the U.S. has suggested Warsaw consider sending one of its systems to shore up air defenses in the Middle East.

On Tuesday, the U.S. president posted on social media his unhappiness with France’s refusal to allow planes with military supplies use its airspace. “The U.S.A. will REMEMBER,” Trump wrote.

European leaders have been walking a fine line since the U.S. and Israel launched their war on Iran Feb. 28. They hope to avoid antagonizing the U.S. commander in chief and keep him from undermining Ukraine’s war effort against Russia. After initially rebuffing Trump’s calls for help to secure passage through the Strait of Hormuz, they have since coalesced around an offer to build a coalition to enforce freedom of navigation in the key passage after the end of active combat.

But it was too late to avoid Trump’s fury. Secretary of State Marco Rubio was softer behind closed doors at a Group of Seven gathering last week in France, making no concrete demands and supporting this initiative, Bloomberg reported. Yet on Monday he said the U.S. may need to reassess its relationship with NATO after the Iran war and called the military alliance’s response to the U.S. action “very disappointing,” assailing partners in the North Atlantic Treaty Organization for denying access to military bases.

After Trump lashed out at France on social media, the French presidency expressed surprise at the American president’s post.

“France’s position has not changed since day one, and we confirm this decision, which is consistent with France’s position since the start of this conflict,” according to a statement from the office of French President Emmanuel Macron.

While the U.S. initiated the war in Iran with little to no warning to allies, its offensive relies heavily on European territory — bases, ports and airspace. Yet European nations are neither willing to engage in the conflict directly nor do they have the political latitude to give Trump the support he wants.

Closing wide swathes of southern European airspace means bombers operating out of the U.K. would have to take a circuitous path to the Persian Gulf. That adds time and strain on flight crews, and requires much more fuel, provided by aerial tankers. The U.S. suffered a tanker mishap earlier in the war, when a KC-135 crashed in Iraq, killing all six crew members.

Europe has skin in the game when it comes to the vital Strait of Hormuz, which Iran closed with threats of retaliation after being attacked by the U.S. and Israel. The critical passageway for energy supplies has been effectively shut since late February, leading oil and gas prices to soar.

The conflict is broadly unpopular across Europe, which is already reeling from an inflation surge that’s stemmed from the war. Leaders have sought to distance themselves from it, stressing that any military involvement so far has been purely defensive.

“We’re seeing evidence of confusion and tension between public opinion and political opinion in many NATO countries,” said Ian Lesser, distinguished fellow at the German Marshall Fund. “As a default, there is a tendency to be helpful in Europe regarding military-to-military cooperation with the U.S., but the current war is putting these longstanding defense relationships under strain.”

The latest tensions add another layer of mistrust and lack of predictability to an already strained transatlantic relationship, he said, adding that “even for those inclined to help it reflects concern about what Europe is getting from having a more helpful posture or what the cost of opposition would be.”

A main focus of U.S. anger has been Spain, which closed its airspace to American flights involved in Iran operations and blocked the use of U.S. bases in Spain. Prime Minister Pedro Sánchez has been one of the most vocal critics of Trump among European leaders, accusing the U.S. president of starting an “illegal” war.

U.K. Prime Minister Keir Starmer also faced harsh criticism from Trump after initially rejecting the president’s request to allow the U.S. to access the country’s military bases to help carry out strikes on Iran. The U.K. government has since allowed the U.S. to use bases for “limited defensive action.”

In a similar vein, Portugal has adopted a cautious stance on U.S. use of the Lajes Air Base in the Azores, granting access under existing bilateral and NATO arrangements while emphasizing it is not a party to the conflict. Lisbon has restricted the authorization to logistical support, including refueling and transit, rather than offensive operations, framing the move as consistent with domestic law and international obligations.

Foreign Minister Paulo Rangel said any authorization is limited to defensive, proportionate operations against military targets, insisted Portugal “will not be in this conflict,” and clarified that no strike missions have been launched from the Azores.

In the case of Italy, the ban on using the Sicily bases was not permanent and relations with the U.S. remained good, a person familiar with the matter said. Italy denied the aircraft landing because the planes were already in the air once the request for combat use was made, the person added, leaving no time to discuss the matter in Parliament.

“We have not registered any friction or issues with our international partners,” according to a statement from the Italian government. “Relations with the U.S. in particular are solid and key to a full and loyal collaboration.”

In contrast to other allies, Romania has allowed the U.S. to use its base there for logistics.

“Every country that joined NATO did so voluntarily; no one forced us,” Romanian Prime Minister Ilie Bolojan told France’s Le Figaro newspaper. “A political divorce between the E.U. and America would be a catastrophe for the entire Western world.”

For his part, German Chancellor Friedrich Merz has ruled out prohibiting U.S. use of its base in Ramstein, its biggest in Europe. An agreement signed after World War II guarantees the U.S. the use of the site as long as its military operations don’t violate national or international law.

That said, Merz, who has sought to curry a close relationship with Trump, has sharply criticized the U.S. attack on Iran.

“What Trump is doing right now is not de-escalation and an attempt to find a peaceful solution, but a massive escalation with an uncertain outcome,” Merz said at a conference in Frankfurt Friday.

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—With assistance from Sofia Horta e Costa, Donato Paolo Mancini, Arne Delfs, Alessandra Migliaccio, Andra Timu, Gerry Doyle and Samy Adghirni.

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