Fact check: How can a country actually withdraw from NATO?

Recent weeks have seen US President Donald Trump escalate his criticisms of NATO, particularly as tensions rise in the Persian Gulf. His remarks, which likened the alliance to a “paper tiger,” followed a lack of coordinated response from NATO members to his request for a naval force to secure the Strait of Hormuz. This strategic waterway has been under Iranian control, prompting Trump to question the alliance’s effectiveness.

Under the 1949 North Atlantic Treaty, Article 13 outlines the formal process for withdrawal. A nation wishing to leave must notify the United States, which then informs the other members. After a year, the country officially exits the alliance. While this procedure seems clear for European nations and Canada, it raises questions about the US’s ability to exit unilaterally.

The US holds a dual role in NATO as both a member and the treaty’s depositary. This means it manages the agreement’s text and handles notifications for withdrawal. To leave, the American government would need to inform the Department of State and subsequently alert all other members. However, the US could remain as the depositary without being a full member, though other countries might pass amendments to transfer this responsibility.

Domestic hurdles for US withdrawal

Domestically, the process is more complex. In 2023, President Joe Biden signed legislation as part of the National Defense Authorization Act for Fiscal Year 2024, requiring a two-thirds Senate majority or congressional approval for a president to “suspend, terminate, denounce or withdraw” from the treaty. The law also bans the use of federal funds to support such a move.

“The law makes it formally very difficult for the president to take the US out of the treaty,” said Rafael Loss, a policy fellow at the European Council on Foreign Relations. “Of course, there might be differing legal interpretations of the competencies of the US’s different legislative branches in the case of Trump attempting to do so.”

This legal framework suggests Trump cannot legally exit NATO without Senate approval. Yet, experts warn that the US could still undermine the alliance by significantly reducing its financial and military contributions. Such an action, while not a formal withdrawal, could erode trust in NATO’s collective defense commitments under Article 5.

“Trump can’t legally withdraw from NATO without Senate consent,” noted Ian Bremmer, president and founder of Eurasia Group, in a post on X. “But if NATO members can’t trust that the United States will honor Article 5, the alliance is already broken in the way that matters most.”

Loss emphasized that even a formal exit would cause substantial harm to NATO, but it might be preferable to a scenario where the US is a passive member. “At least such a move would provide clarity and advance notice to the other members,” he explained, highlighting the potential for litigation over the US’s other commitments to the alliance.