US-Iran War Fallout: The transatlantic alliance that rebuilt the West after World War II and held the line during the Cold War is closer to collapse than at any point in its history, for several reasons. According to a report in the Wall Street Journal, Donald Trump has privately floated the idea of the United States withdrawing from NATO.
What triggered the latest crisis: The war in Iran Europe did not sign up
The immediate fault line is the US-Israeli military campaign against Iran, a war that European governments have not been consulted about, do not recognize as legal, and have refused to join.
Trump reacted furiously, according to a WSJ report, citing people familiar with his private conversations. The US president has reportedly expressed “disgust” at European allies for staying away, and has discussed with advisers and journalists the possibility of the US withdrawing from the alliance altogether.
That sentiment was echoed this week when Trump told Britain’s The Telegraph: “We would always be there for them. They weren’t there for us.” According to him, European assistance with the Strait of Hormuz should be “automatic”, just as the US automatically supported Ukraine, which “wasn’t our problem”.
Europe’s reaction: We were never obliged to join your war
European governments were not passive. Several, including France, the United Kingdom, Italy, and especially Spain, have imposed explicit restrictions on how the U.S. can use its air bases and airspace to prosecute Iran’s campaign. Requests to deploy European naval forces in the Strait of Hormuz while active hostilities continue have been unequivocally rejected.
The legal basis for this refusal is clear, European officials say. NATO’s founding charter is a mutual defense pact covering Europe and North America. It places no obligation on member states to participate in US military campaigns of choice in the Persian Gulf or anywhere else outside that geographical extent.
What makes Europe’s stance particularly emphatic is the reminder of what the alliance has already delivered. Since NATO’s founding in 1949, its collective defense clause has been triggered exactly once, after the September 11 attacks in 2001. European nations answered the call, sending troops to Afghanistan and suffering several thousand casualties fighting alongside American forces. Trump’s suggestion in January that those allies had withdrawn from front-line fighting was factually incorrect, European diplomats noted.
“The outrage over these comments in Europe was palpable and deep, in a way that many in the US did not register,” the WSJ quoted Philippe Dickinson, a former British diplomat and deputy director of the Transatlantic Security Initiative at the Atlantic Council, as saying.
A formal withdrawal would face legal and political obstacles in Washington
Pulling the US out of NATO is not, in practice, something the president can do by executive order. Congress passed legislation in 2023 that states the president cannot withdraw from the NATO treaty without the consent of the Senate by a two-thirds majority or a new act of Congress. That provision was co-sponsored by Marco Rubio, now Trump’s secretary of state.
In the Senate this week, Mitch McConnell and Chris Coons issued a rare joint statement across party lines affirming that NATO serves America’s national security. Legislative pressure is real, if not overwhelming.
Military historian Phillips O’Brien of the University of St Andrews pointed to other limitations: “Congress would be reluctant, the US still wants to sell weapons to European allies, and withdrawal would reduce US influence in world affairs.”
Some European officials are reading Trump’s threats as more of a pressure campaign than real intent, an attempt to win more European support for the Iran operation through the threat of withdrawal. Polish Foreign Minister Radoslaw Sikorski was less optimistic, writing on X that allies must take the breakup scenario seriously: “Of course we want to be a good, loyal ally of the United States, but we can’t pretend that the American president doesn’t say what he says.”
Britain turns to Europe. The signal is unmistakable.
The clearest sign of the alliance’s shifting center of gravity may come from London. British Prime Minister Keir Starmer, whom Trump has publicly humiliated on numerous occasions, announced this week that Britain would reorient its economic and security posture towards Europe.
After a year that included US tariffs on European goods, the near-abandonment of Ukraine, mockery of European leaders and threats to seize Greenland from Denmark, European public opinion has hardened considerably. Governments that would otherwise seek compromise are constrained by voters who have run out of patience.
“The United States will become a lonelier superpower, which will be more expensive for them,” Fabrice Pothier, CEO of geopolitical consultancy Rasmussen Global, told the Wall Street Journal. “Trump is kicking and screaming because he made a unilateral move only with Israel and now he realizes it’s a pretty heavy lift.”
What happens next: An alliance that could dissolve without anyone formally ending it
US officials say no decision has been made and NATO has survived crises before. But the scenario most feared by its architects, not a dramatic breakdown but a slow drain on credibility and commitment, is now a real possibility. The US could remain a signatory to the treaty while reducing its military presence in Europe, making it clear in word and deed that Article 5 guarantees are conditional.
European defense budgets are growing, but the continent is years away from being able to guarantee its own security without American support. The urgency of this transition has never seemed more urgent or the timeline more uncertain.
