The recent exchange between U.S. President Donald Trump and NATO figures has revived questions about whether Washington could actually sever ties with the alliance. What began as heated public claims — including suggestions that the U.S. might consider a formal withdrawal after allies declined to join an American-Israeli campaign against Iran — quickly collided with legal and geopolitical realities. Ahead of a scheduled meeting with NATO Secretary General Mark Rutte, White House communications amplified the rhetoric; press secretary Karoline Leavitt was quoted saying the alliance had “tested and failed,” a line that fed speculation but did not by itself change treaty obligations.
Despite dramatic social media posts and a steady stream of warnings, the drama on the diplomatic stage produced less immediate upheaval than many expected. In a public address the president mostly avoided attacking alliance structures directly, while posting on his platform that “NATO wasn’t there when we needed them, and they won’t be there if we need them again.” Meanwhile, European leaders, including Rutte, publicly reaffirmed that NATO remains an important partner to the United States. The tense backdrop also included a fragile ceasefire with Iran and earlier threats that escalated the crisis, underlining how military crises and alliance politics are now tightly interwoven.
Why the mechanics of leaving NATO are steep
Pulling the United States out of NATO is not just a political declaration; it runs into legal and institutional barriers. A recent fact-check noted a 2026 law that constrains unilateral withdrawal, and later legislative steps imposed in 2026 mean a full exit would likely need substantial congressional backing — including a supermajority in the Senate. On top of that, the Washington Treaty itself contains an Article 13 mechanism for denunciation — a one-year notice procedure that has never been used. Public opinion adds another layer: a Pew Research study showed broadly positive views of NATO among Americans, with a clear majority seeing alliance membership as beneficial, even as support among Republicans has slipped below 50 percent.
Ways Washington could erode rather than end the alliance
Analysts and former diplomats outline several paths that would damage NATO without a formal divorce. One approach is a gradual or stealth withdrawal: remain a member on paper while refusing to fill key posts, lagging on appointments and payments, and weakening day-to-day cooperation. A second is tactical non-participation: failing to mobilize during crises or reducing forward forces — for example, scaling back the U.S.-led deterrent presence in eastern Poland, which numbers roughly 10,000 troops. The most extreme option is issuing a 180-day formal notice under the Treaty. Officials quoted anonymously have also suggested Washington could opt to punish individual countries that did not back U.S. moves on Iran rather than dismantle the alliance wholesale.
Short-term measures and longer-term risks
Even limited steps to withdraw capacity would carry heavy consequences. Not showing up in a crisis would erode NATO’s collective defence guarantee in practice, inviting opportunistic behavior from rivals. Canada’s former ambassador to NATO observed that targeting specific allies is plausible within a transactional policy, but continual public attacks that tie grievances to NATO itself already cause reputational harm. Economically, leaving or reducing commitments would jeopardize access to European bases and reduce international markets for the U.S. defence industrial base, increasing long-term costs for American suppliers.
What Europe would have to do if the U.S. stepped back
Researchers at the International Institute for Strategic Studies mapped a hypothetical NATO without U.S. support and concluded Europe is not currently equipped to substitute for American capabilities. Replacing major U.S. platforms and some 128,000 troops, along with space assets and wide-area intelligence, surveillance and reconnaissance systems, would require an estimated extra US$1 trillion on top of already rising defence budgets. Former U.S. ambassador Ivo Daalder has argued that making NATO more European would demand three scarce things: money, time and continued U.S. co-operation. Retired Canadian general Tom Lawson has also warned that trust in Washington is fraying after volatile rhetoric surrounding the Iran crisis.
Security implications for the transatlantic pact
Perhaps the most immediate danger is strategic: if adversaries conclude NATO’s deterrence is weakened, the alliance’s ability to prevent aggression could be undermined. Recent actions by Russia, including probing undersea cables near the United Kingdom, are cited as evidence that Moscow is testing NATO resolve. The net result is a paradox: while a formal U.S. exit faces steep political and legal obstacles and lacks broad domestic support, ongoing public attacks on the alliance and selective punitive measures could materially degrade NATO’s effectiveness without ever triggering the treaty’s formal exit clauses.
