Europe is increasingly confronting an unthinkable scenario: a North Atlantic Treaty Organization (NATO) without the United States, as deepening divisions over the Iran conflict push the alliance into what analysts describe as its most severe crisis in decades.
Tensions have escalated sharply following US President Donald Trump’s aggressive rhetoric on Iran and repeated criticism of NATO, which he recently dismissed as a “paper tiger.” The remarks have intensified concerns across European capitals about Washington’s long-term commitment to the alliance.
Former US ambassador to NATO Ivo Daalder warned that the alliance is “not dead” but “deeply damaged,” pointing to a growing trust deficit between the United States and its European partners. He described the current moment as the “worst crisis” in NATO’s 77-year history, dw.com reports.
The strain goes beyond rhetoric. Several European governments have refused to support Washington’s military posture on Iran, with some denying the US access to bases and airspace for offensive operations. According to Daalder, this marks a significant shift, reflecting a belief among European allies that the US is becoming an unreliable partner.
NATO Secretary-General Mark Rutte has sought to downplay the divisions, emphasizing that differences among allies are not unusual. However, his support for US efforts to curb Iran’s military capabilities has done little to bridge the widening gap.
At the heart of the debate lies uncertainty over whether Washington could withdraw from NATO altogether. While US law requires significant congressional approval for such a move, Trump has suggested he could bypass these constraints, raising the prospect of a constitutional showdown.
Even without a formal exit, experts warn that the US could effectively weaken NATO by scaling back troop deployments, reducing participation in joint commands, or withdrawing from key leadership roles traditionally held by American officials.
For Europe, the implications are profound. While NATO could survive without the US, analysts say it would require a massive transformation. European members would need to dramatically increase defense spending, replace critical US military capabilities, and assume greater leadership within the alliance.
Studies suggest this transition could cost European countries up to $1 trillion, alongside efforts to close gaps in intelligence, surveillance, and advanced military systems.
Despite the challenges, some European policymakers argue the continent has the capacity to stand on its own. Discussions are already underway about enhancing regional defense cooperation, including potential expansion of nuclear deterrence frameworks led by countries such as France.
Still, uncertainty looms large. As NATO leaders prepare for high-stakes talks in Washington, the alliance faces a defining question: whether it can adapt to a shifting geopolitical landscape, or risk fragmentation under the weight of transatlantic discord.
