The "most important question for Europe is whether the United States is prepared to be as loyal as our (NATO) treaties provide." This statement was made by a European leader in an interview published on April 24 in the Financial Times. Was it the French President? The Spanish Prime Minister?
No. The remark came from Polish Prime Minister Donald Tusk. It is therefore the leader of the country considered the most Atlanticist in Europe who is questioning the American commitment to NATO. Such a stance would have been unimaginable just a few years ago and, in itself, illustrates the growing mistrust towards the American ally.
Trump's Second Term: A Breaking Point
In late December, we already noted that 2025 marked a rupture between Europe and the US. This rift appears to be widening in 2026. Donald Trump began the year by threatening to seize Greenland by force, despite the territory being under the sovereignty of Denmark, a member of NATO. Europeans have since shown openness to increased efforts to secure Greenland, as well as a reinforced American presence through new bases.
Tensions reached a fever pitch just days before the Davos summit. Donald Trump was then threatening to impose 200% tariffs on French wines and champagnes. However, European firmness and mediation by NATO Secretary General Mark Rutte eventually led the American president to back down.
Davos World Economic Forum, January 21, 2026
Tactically, at least. This has indeed been a long-standing obsession. In 2019, he had considered buying Greenland, which had already sparked a diplomatic crisis with Denmark. And on April 6, at the conclusion of a press conference dedicated to the situation in Iran, he ended his remarks with this charge against NATO: "It all started, if you want to know the truth, with Greenland. We want Greenland. They don't want to give it to us. So I said: 'Bye bye!'"
Making Europeans Pay
The threat of a NATO withdrawal has been brandished by Donald Trump since his first term. The American president has always lambasted this alliance which, in his view, places the burden of European defense on the American taxpayer. This is a justified critique, as European governments slashed military budgets after the Cold War ended. However, this purely mercantilist vision ignores the strategic interest of NATO for the United States. The alliance also serves as a formidable outlet for the American defense industry.
In his book "Watchman of the World," former NATO Secretary General (2014-2024) Jens Stoltenberg details the behind-the-scenes events of the 2018 Brussels summit, where Trump shook the Atlantic Alliance. He describes a meeting in which the American president handed out praise — and especially criticism — to his counterparts.
"Trump took the floor again and listed member states' contributions as a percentage of GDP, as if he were announcing Eurovision song contest results: 'Belgium: 0.9. Less than 1%. Croatia: Oh, I'm so disappointed, I can't believe it: 1.26%. You must feel pathetic,' he said, scanning the room for the relevant representative. 'Estonia: 2%. Thank you! France: 1.79%. Not bad, Emmanuel. Not bad for you. You haven't been president long enough; it will surely plummet. Germany: 1.2%. Come on, Angela! Finally!' Then, addressing Xavier Bettel, Prime Minister of Luxembourg: 'Luxembourg, you're such a nice guy, where do you stand? 0.46%. I'm not talking to you anymore. But it's okay. My wife thinks you're a great guy.'"
It is likely to avoid such meetings that NATO is considering ending the organization of annual summits, according to reports from Reuters.
NATO Summit, Watford (United Kingdom), December 4, 2019
Since that 2018 summit, the war in Ukraine has pushed Europeans to step up their defense spending. By 2025, all countries had reached the 2% of GDP target (there were only 3 in 2014). Pressure from Donald Trump even led the 32 members of the Atlantic alliance to raise this target to 5% of GDP last year during the Hague summit (3.5% for defense in the strict sense and up to 1.5% for peripheral defense-related spending — infrastructure, cybersecurity, etc.).
Donald Trump has thus succeeded in making his NATO allies pay. However, this budgetary effort does not seem enough to satisfy the tenant of the White House.
Iran as an Accelerator
The war in Iran has appeared to further increase divisions between Americans and Europeans. Donald Trump has reproached the latter for failing to provide support, in return questioning his commitment to NATO. European leaders, meanwhile, believe that this war is not theirs and point out that the United States started this offensive without consulting them.
In late April, Reuters revealed the existence of an internal Pentagon email discussing potential sanctions against NATO allies deemed to be failing. Amongst the measures considered were a suspension of Spain from the Alliance and a revision of the American position on British sovereignty over the Falkland Islands.
On Friday, Donald Trump took action by announcing the withdrawal of 5,000 American troops from Germany. Concurrently, the White House is expected to cancel a project to deploy long-range missiles in Germany, according to the Wall Street Journal and CBS. Donald Trump's decision followed comments by Chancellor Merz, who suggested that the United States was being "humiliated" by Iran.
Ramstein Air Base (Germany)
Germany is the European country hosting the largest American contingent in Europe, with 36,000 soldiers. European bases are vital staging points for American forces. This has been one of the points of friction between Americans and Europeans for two months, as some countries have refused to allow their bases to be used for strikes against Iran.
If European leaders no longer hesitate to display their dissatisfaction, or even to oppose Donald Trump, it is also because public opinion has shifted. In Spain, Italy, and France, more people now view the US as a threat rather than a close ally, according to a Politico poll.
Doubts Over American Commitment
However, the reduction of the American military presence in Europe may not be the most worrying element. The United States probably needs operational capabilities in other theaters (the Middle East today, Asia in the longer term), while the strengthening of European armies should allow them to take over.
What is more concerning is that, already, NATO Allies no longer seem certain that the Alliance would fulfill its role in case of need.
The foundation of NATO is Article 5, which stipulates that an attack against one member is considered an attack against all. In other words, the Alliance's credibility rests on the conviction that all Allies will intervene if a NATO country is attacked.
Yet, Donald Trump has several times expressed doubt regarding the Allies' commitment to defending the United States if the latter were attacked. On April 6, he even suggested that NATO is a "paper tiger." This doubt is now reciprocal, as expressed by the Polish Prime Minister. This loss of trust undermines NATO's deterrence capability.
This climate is leading Europe to take more of its destiny into its own hands. According to the Wall Street Journal, several countries are working on a "European NATO" — a fallback plan to ensure Europe's defense in the event of a US departure. EU countries are also considering a doctrine for the use of their mutual assistance clause — Article 42, paragraph 7 of the EU Treaty. Other formats are also emerging on defense issues, such as the coalition of volunteers for support to Ukraine, led by France and the UK.
In their rhetoric, however, European leaders deny wanting to distance themselves from the United States, often referring to the "European pillar of NATO." However, in practice, Europeans are indeed preparing for the possibility of having to manage without the Americans. During a visit to Greece in late April, Emmanuel Macron summarized the sentiment toward the American ally: "No one is entirely sure that this ally is reliable."
