The president of the United States, Donald Trump, threatened last night to withdraw his country from NATO. It is the second time in less than a week that he has done it. The forcefulness of his words is increasing: now he says that the Atlantic Alliance “was not there” when he needed it and that “it will not be there” when he needs it again. The example he set is not even his allied solitude in the face of his attack on Iran, but rather that arctic whim called Greenland.
In response to the snub, the magnate is considering various degrees of protest, ranging from sanctions on countries that do not align with his policies to the withdrawal of forces on European soil, including the abandonment of the institution itself, something that he discussed yesterday with his secretary general, Mark Rutte.
The Dutchman assured in an interview with CNN, after the meeting at the White House, that Trump was “clearly disappointed” with the Alliance, but that he was also “receptive.” He believes that he “listened carefully” to his arguments about what is happening in Europe regarding the war in Iran, for example. “It is true that not all European nations fulfilled their commitments. I perfectly understand their disappointment!” Rutte emphasized, justifying Trump’s recent reproaches against the rest of the partners. Again, in his line, supporting the North American.
The Wall Street Journal publishes this morning, citing senior US Government officials, that the White House is considering a plan to sanction some NATO members who did not contribute to its and Israel’s interests during the war against Iran. Spain, for example, denied the use of the bases of Rota (Cádiz) and Morón de la Frontera (Seville) for this contest and also vetoed the use of its airspace to the planes used in the operation, called Epic Fury.
The proposal, the newspaper details, would involve the transfer of US troops from NATO member countries considered harmful to the war effort against Iran to countries that did provide support. He cites Spain and he cites Germany. Although it is a forceful step, the proposal is far from the threat to completely withdraw the US from the Alliance.
But can he do that, something so disruptive, abandoning a decades-old commitment that has been central to his nation’s foreign policy? In El HuffPost We review what the laws say.
What the American Constitution says
By law, the US is not supposed to leave NATO without congressional approval. Experts say it is unclear, however, whether Trump could act unilaterally to abandon the 77-year-old transatlantic coalition because he frequently makes major decisions without House approval. We have already had a few, from the current war in Iran (let’s continue calling it that despite the fact that there has been a ceasefire since yesterday) to the attacks on alleged drug boats in the Caribbean, with the final incident of the kidnapping of Nicolás Maduro in Venezuela.
There are already several internal decisions, not only international politics, applied with this same order and command. For example, there have been in immigration matters. Several of them have been blocked by US courts precisely because they do not comply with the law.
The Constitution, specifically, specifies that the president has the power to make treaties with the advice and consent of the Senate, as long as two-thirds of the 100 members of the Senate agree. However, it does not comment on the withdrawal of treaties.
What does the NATO Treaty itself say?
NATO, made up of 32 European countries, the US and Canada, was formed in 1949 with the aim of countering the risk of a Soviet attack and, since then, has been the cornerstone of Western security.
Article 13 of the 1949 North Atlantic Treaty, the founding one, establishes that any party can withdraw after giving one year’s notice to the United States government, which in turn will inform other governments of the “notification of denunciation.”
To date, no NATO member has renounced its membership. France did leave the military structure of the bloc, since it did not want its troops or its nuclear bombs to be under the military command of the Brussels headquarters and soldiers of other nationalities. It was like this for 40 years, between 1966 to 2009, but it always remained in the political agreement and fulfilled its obligations as an ally.
And American law?
In 2023, Congress approved – and then-President Joe Biden, a Democrat, signed into law – a law that prohibits any US president from suspending, terminating, denouncing or withdrawing the country from the treaty that established NATO, unless the withdrawal is supported by a two-thirds majority in the 100-member Senate.
The legislation was introduced as an amendment to the National Defense Authorization Act of 2024, a sprawling annual bill that sets Pentagon policy. The main sponsors of the amendment were Democratic Senator Tim Kaine of Virginia and then-Republican Senator Marco Rubio of Florida.
Rubio, who is now Trump’s Secretary of State and National Security Advisor, declared last Tuesday that Washington would have to reassess its relations with NATO after the war with Iran, which also demonstrates a shift in his thinking, who knows if only out of support for the president or because he seeks to be his successor in the 2028 elections.
The amendment also stipulated that no US funds could be used for a NATO withdrawal.
What Trump has said so far
Trump has harshly criticized NATO for years, this is not something new. In 2020, during his first term, the Justice Department’s general counsel issued an opinion stating that the president, not Congress, has the exclusive authority to withdraw from treaties.
A February 2026 report published by the Congressional Research Service indicated that if the issue were raised in court, the executive branch could cite that opinion and argue that the amendment is unconstitutional.
Trump declared last week that he was “absolutely” considering withdrawing from the Alliance, citing its “unpleasant” relationship with NATO. “We will not forget what has happened,” he said, alluding to that situation of isolation in the face of his barrage in Iran, which has been meme fodder on social networks for weeks. Trump’s statements came just hours after his Secretary of Defense, Pete Hegseth, refused to reaffirm the US commitment to NATO’s collective defense, set out in Article 5.
The president later said in an interview with The Telegraph: “I always knew that NATO was a paper tiger and Putin knows it too, by the way”, and the final sentence: “I am considering leaving NATO.”
Now, it has been the White House spokesperson, Karoline Leavitt, who has brought up the matter again. In a press conference yesterday, he confirmed that the president was going to directly ask Rutte about leaving the defensive club.
Experts noted that lack of commitment, more than any law, is the key point. “If the president and the military are not committed to NATO and European security, then I don’t think Congress can do much to stop it,” Max Bergmann, a former State Department official and current director of the Europe, Russia and Eurasia Program at the Center for Strategic and International Studies, told Reuters.
The US represents about 70% of all NATO military spending. It also represents about 40% of the entire military and has 91% of the nuclear warheads. And, above all, it now has the missile interception infrastructure, the NATO anti-missile shield in Europe, so without them, vulnerability grows. Above all, it completely changes the world defense pattern with which the West was equipped after the Second World War.
What happens now?
Under international law, a nation’s head of state generally has the authority to withdraw from a treaty, if the treaty allows it and the nation adheres to the withdrawal process.
U.S. legislation has been less clear, although presidents have withdrawn from several treaties without congressional approval, including Trump’s withdrawal in 2020 from the Open Skies treaty, which allows unarmed surveillance flights over member countries.
If the matter goes to court, challenging Trump’s decision would face major obstacles. Among them, determining who has procedural standing – a personal interest in the result – to challenge the withdrawal.
The US Supreme Court, whose conservative majority often rules in favor of Trump, has never examined a treaty withdrawal case on the merits.
