For many years, President Donald Trump has expressed strong skepticism toward NATO, repeatedly questioning its usefulness and the commitment level of European member states. Since the escalation of the conflict involving Iran, his criticism has become even more intense, with several recent statements suggesting he is seriously considering withdrawing the United States from the alliance entirely.
In a recent interview with the British newspaper The Telegraph, Trump indicated that he is reevaluating the United States’ participation in NATO. He reinforced this position in a separate conversation with Reuters, where he stated that he was “absolutely” considering the possibility of pulling the US out of the alliance.
Trump’s frustration appears largely tied to what he sees as insufficient support from European countries, particularly in relation to the ongoing conflict with Iran. He has openly criticized US allies for failing to contribute more actively, especially when it comes to securing the Strait of Hormuz, a key global oil shipping route that has been heavily affected by rising tensions in the region.
Despite Trump’s claims that he could remove the United States from NATO, the legal framework surrounding such a move is far more restrictive. In 2023, Congress passed legislation specifically designed to prevent a president from unilaterally withdrawing from the alliance. Under this law, any attempt to leave NATO would require approval from two-thirds of the Senate or a separate act of Congress.
This measure received bipartisan support. It was co-sponsored by then-Senator Marco Rubio, who currently serves as Secretary of State, and Democratic Senator Tim Kaine of Virginia. The provision was later included in the 2024 National Defense Authorization Act, solidifying it as binding law.
The practical implication of this requirement is significant. Even if all Republican senators supported Trump’s proposal, it would still require backing from a number of Democrats—at least 14, assuming full attendance—to reach the necessary threshold. Given the current political divisions, such support is highly unlikely.
Several lawmakers have already spoken out against the idea. Senator Thom Tillis of North Carolina, a leading Republican involved in NATO-related discussions, has rejected the notion that the president can act alone. In a March interview on ABC’s “This Week,” he stated clearly that it is “factually not true” that Trump could withdraw from NATO without congressional approval.
Tillis acknowledged that while a president may not have the legal authority to formally exit the alliance, they could still weaken it in other ways. “The president of the United States cannot withdraw from NATO. Now, having said that, the president can poison the well. The president can make it functionally defunct if he wants to,” he said.
He also pushed back against Trump’s criticism of allied nations, including remarks where Trump labeled them “cowards” for not offering more assistance. Tillis emphasized that such a decision should involve military leadership, noting the serious risks involved. “You’d be hard pressed to find one, because that has enormous, enormous risk in it. American lives have been saved by the NATO alliance, and American lives will be lost in great numbers without it,” he added.
On the Democratic side, Senate Minority Leader Chuck Schumer also responded strongly to Trump’s comments. Writing on social media, he made it clear that Congress is unlikely to support such a move. “The Senate will not vote to leave NATO and abandon our allies just because Trump is upset they wouldn’t go along with his reckless war of choice,” Schumer said.
He also expressed appreciation for the 2023 legislation that now limits presidential authority in this area. Referring to Rubio’s role in sponsoring the bill, Schumer added, “Thank you to @SecRubio for sponsoring the bill in 2023 requiring a two thirds vote of the Senate to make sure clueless presidents couldn’t act on a whim.” He echoed Rubio’s earlier statement that “No U.S. President should be able to withdraw from NATO without Senate approval.”
Despite the existence of this law, the issue is not entirely settled from a legal perspective. According to a report from the Congressional Research Service, if a president attempted to withdraw from NATO without congressional approval, the matter could ultimately be decided in court.
Legal experts note that presidents have historically acted independently when withdrawing from international agreements. A 2020 opinion from the Department of Justice’s Office of Legal Counsel suggested that the president holds significant authority over treaties.
Curtis A. Bradley, a law professor at the University of Chicago, explained that “In practice, presidents have often acted unilaterally in withdrawing the United States from treaties, especially during the last 50 years or so.”
However, he also pointed out that the 2023 law signed by President Joe Biden directly challenges that precedent. If Trump were to proceed without congressional approval, Bradley argued, “he would be violating the statute.”
Trump’s legal team would likely argue that the law itself is unconstitutional, claiming it interferes with the president’s authority over foreign relations. However, Bradley considers this argument weak. He emphasized that since Congress plays a required role in approving treaties under the Constitution, it is reasonable to conclude that it should also have a say in withdrawing from them.
Ultimately, the debate reflects a deeper constitutional question—one that could lead to a significant legal battle if tested. Beyond the legal complexities, however, the potential withdrawal of the United States from NATO would have far-reaching global consequences, reshaping alliances and altering the balance of international security.
For now, despite strong rhetoric and political tension, the combination of legal safeguards and bipartisan opposition makes such a move difficult to achieve in practice.
