What happens if US withdraws from Nato and United Nations?

Is the US opting out of Nato? That’s the question everyone is asking after ‘First Buddy’ Elon Musk shared his support for the same on his social media platform, X, on Saturday (March 1).

Notably, Musk isn’t alone in his support for America’s exit from the military alliance. Several Republican lawmakers have questioned Washington’s membership in Nato, with some even calling for an immediate pullout from the alliance.

These comments have been amplified over the weekend after US President Donald Trump got involved in a heated exchange with Ukrainian President Volodymyr Zelenskyy at the White House on Friday (February 28).

But can the US president actually quit Nato? And what would it mean for the US and the world if Trump heeded Elon Musk’s advice?

What did Musk, Republicans say about US exit from Nato and UN?

As the world watched perhaps this decade’s biggest diplomatic disaster — T rump berating Ukraine President Volodymyr Zelenskyy — unfolding on live television, Elon Musk, the head of Department of Government Efficiency (Doge) took to X to endorse a suggestion by user @GuntherEagleman, who wrote: “It’s time to leave Nato and the United Nations (UN).”

Responding to @GuntherEagleman’s post, Musk wrote, “I agree”. However, he did not elaborate on the specifics of why he wants the US to pull out of Nato and the UN.

More from Explainers

How Trump has fixed a price for America’s goodwill As Trump flirts with Russia, allies grow wary of sharing intelligence with US: Report

Other Republicans have also voiced this sentiment. Utah Senator Mike Lee, who has criticised Nato for quite some time, has said that the alliance is a “great deal for Europe” but a “raw deal for America.”

“Get us out of NATO,” Lee wrote on X.

Time to leave NATO

Let’s go!

Who else is with President Trump on this! https://t.co/tLkpWWaU5q

— Mike Lee (@BasedMikeLee) February 16, 2025

He had also introduced legislation last month alongside other lawmakers to pull out of the UN, decrying it as “a platform for tyrants and a venue to attack America and her allies.”

Editor’s Picks

1

How Trump triggers major upset in US-NATO ties 2

What happens if the US pulls support from IMF, World Bank?

Thomas Massie, the US representative from Kentucky, also called for America to quit the alliance, writing, “Nato is a Cold War relic that needs to be relegated to a talking kiosk at the Smithsonian.”

What has been Trump’s stance on Nato?

Interestingly, US President Donald Trump has also been critical of the military alliance. When he ran for president the first time around, he frequently called the alliance “obsolete” and in August 2019, he even said, “I don’t give a s**t about Nato”, according to his former National Security Advisor John Bolton.

The Politico citing a senior EU official reported that Trump privately warned that America would not come to the European Union’s aid if it was attacked militarily.

“You need to understand that if Europe is under attack we will never come to help you and to support you,” Trump told European Commission President Ursula von der Leyen in 2020, according to French European Commissioner Thierry Breton, who was also present at a meeting at the World Economic Forum in Davos.

“By the way, Nato is dead, and we will leave, we will quit Nato,” Trump also said, according to Breton.

In his second tenure too, Trump has been critical of Nato. Just days after his inauguration, Trump said the US was protecting members of the alliance, but they were “not protecting us.” He also pushed for Nato members to spend five per cent of their GDP on defence, a level far above the current two per cent goal and a level that no member state, including the US, currently satisfies.

He also complained that the US contributes too much to its budget while EU members spend too little on defence. According to data, the US contributes about one-sixth of Nato’s annual budget. Washington financed 15.8 per cent of the military alliance’s yearly expenditure of around $3.5 billion. It’s the joint largest share, alongside Germany’s, according to a Nato breakdown for 2024.

But can Trump withdraw from Nato and UN?

However, even as Republicans, Musk and Trump show scepticism towards Nato, the US’ exit from this group is easier said than done. Experts note that a withdrawal would trigger a legal headache for the US president.

How would this happen?

In 2023, Senators Tim Kaine and Marco Rubio authored legislation requiring that any presidential decision to exit Nato must have either two-thirds Senate approval or be authorised through an act of Congress. Lawmakers passed the measure as part of the fiscal 2024 National Defense Authorization Act, which President Joe Biden signed into law.

Karen Sokol, a legislative attorney for the Congressional Research Service, noted that this law prohibits unilateral presidential withdrawal from a treaty.

However, other experts differ, saying that the law isn’t airtight and that the US president could bypass it. Scott Anderson, a Brookings Institution scholar and senior editor of Lawfare, said, “This is not open and shut, this is about Congress telling you you can’t do this, and if you ignore Congress, you’re going to have to fight us in the courts over it.”

What is more worrying, however, is that even if Trump couldn’t leave Nato, he could undermine it or as Kathleen J McInnis, a senior fellow in the International Security Program, noted in Lawfare that Trump could ‘ quiet quit’ Nato.

In the case of the UN, the UN Charter is a binding treaty, which contains no provision for voluntary withdrawal. Thus, according to the 1969 Vienna Convention, it would not be technically permissible unless there had already been a material breach of the treaty by another party.

History shows that Indonesia was the only country to withdraw from the UN from 1965-66 to protest against Malaysia being elected to the Security Council. However, they just showed back up in 1966 and no action was required to reinstate them.

What would be the repercussions if US left Nato and UN?

Catastrophic… That would be the implication if Trump did go ahead and pull out of these two forums.

If the US did go ahead and pull out of Nato, it would spell trouble for not only Europe but also for Washington itself.

James Goldgeier, an international-relations professor at American University and the author of several books on Nato, told The Atlantic that the result would be chaotic. “It’s not like you can say, ‘Okay, now we have another plan for how to deal with this,’ ” he said. There is no alternative leadership available, no alternative source of command-and-control systems, no alternative space weapons, and not even an alternative supply of ammunition. Europe would immediately be exposed to a possible Russian attack for which it is not prepared, and for which it would not be prepared for many years.

Moreover, defence supplies would dry up for Ukraine. The prospect of America leaving Nato would force many European countries to keep their military resources at home. This would lead to the Ukrainians running out of ammunition quite quickly.

But Trump’s potential move could also reverberate outside of Europe and hurt Washington itself. If the US left Nato, then it wouldn’t allow the superpower to maintain a presence in Europe, Africa or West Asia. As National Interest noted that many countries would move closer to Russia or China. “If our allies and partners can’t count on us to be there, we will lose access to many military bases around the globe.”

Trump’s withdrawal from the UN would also be problematic. First and foremost, it would withdraw the US from the global stage — the US’ veto would be revoked and its seat as one of five permanent members of the UN Security Council would go. The US would be effectively surrendering its right to participate in negotiations.

It would also undermine the authority of the UN on a global stage. As the Borgen Project wrote, “If its initial champion, the nation that has hosted the institution’s headquarters from its beginning, was to withdraw, it would create a precedent that erodes the principles on which the UN was founded.”

Funding for the UN would also decrease significantly. In the year 2023, the US contributed almost $13 billion to the United Nations, with the World Food Programme receiving the biggest chunk of the donated proceeds. The Trump administration has already withdrawn from the World Health Organization (WHO), which has affected global health.

Experts also note that by withdrawing from the UN, the US would be losing its hold over global affairs and empowering China. The Foreign Affairs wrote in one report that “US retrenchment empowers only China.” It noted that the US’ withdrawal will push UN agencies into China’s orbit, ultimately making the world less hospitable to US interests.

With inputs from agencies