“We are a sovereign country that does not wish to take part in illegal wars,” Sánchez said. U.S. President Donald Trump responded by threatening a full trade embargo against Spain.

Weeks later, Italian Prime Minister Giorgia Meloni – Trump’s closest European ally and the only EU head of government invited to his second inauguration – broke publicly with Washington.

“When we don’t agree, we must say it,” she said. “And this time, we do not agree.” Rome then refused to refuel U.S. bombers at a base in southern Italy.

These are not minor diplomatic frictions. As a scholar of alliance politics and nuclear security, I see something much larger than a tactical disagreement. The Iran war’s most consequential casualty may not be in Tehran. It may be American credibility as an ally, and with it, the trans-Atlantic alliance itself.

The Iraq comparison misleads

The initial U.S. and Israeli strikes on Iran were launched with virtually no advance consultation with European allies. The Trump administration treated NATO partners not as participants in strategic decision-making but as logistical infrastructure to be commandeered or punished for refusing assistance.

European governments, even those most invested with the U.S., declined to join the campaign. The Trump administration has responded with the embargo threat against Spain and the withdrawal of 5,000 U.S. troops from Germany.

“The U.S.A. will REMEMBER!!!” Trump posted on Truth Social on March 31, 2026.

The reflex in Washington has been to read this as a rerun of 2003, when France and Germany opposed the Iraq War. In January 2003, Defense Secretary Donald Rumsfeld dismissed France and Germany as “old Europe” while courting the postcommunist “new Europe,” including Poland, the Czech Republic and Hungary.

On the surface, the parallel is tempting: a unilateral American war in the Middle East, European refusal to participate, trans-Atlantic recriminations.

But the comparison conceals more than it reveals. In 2003, the United States wanted Europe in its coalition. The George W. Bush administration sought United Nations authorization, courted allies and treated European refusal as a problem to be managed.

In 2026, the Trump administration explicitly does not want European input. It views allies as freeloaders and threatens them with economic coercion. It treats their hesitation as cause for retribution rather than negotiation.

The deeper difference is structural. In 2003, the trans-Atlantic alliance still rested on shared commitments to collective defense, open trade and an international, rules-based order.

Today, the Trump administration does not share the commitments that traditionally bound the United States to its European partners, whether on NATO, the Russia-Ukraine war, or the rules governing trade and migration.

The shared values that papered over the Iraq disagreement in 2003, and that allowed President Nicolas Sarkozy to reintegrate France into NATO’s command by 2009, are no longer there to do the work of repair.

The April 2026 collapse of Viktor Orbán’s 16-year rule in Hungary left Trump without a serious political ally among major European governments.

The real precedent is Suez

A more illuminating precedent lies further back. In 1956, Britain and France went to war with Egypt over the Suez Canal, in coordination with Israel, concealing their plans from the Eisenhower administration. Washington responded by threatening to crash the British pound, forcing London and Paris into humiliating retreat.

The crisis is remembered as the moment Britain accepted that it was no longer an independent great power.

But its more important legacy was strategic. Suez exposed the depth of Europe’s dependence on the United States. That humiliation drove Charles de Gaulle’s pursuit of an independent French nuclear deterrent. It also accelerated European integration and planted the recognition that genuine strategic autonomy would be a generational project.

The Iran war inverts the conditions of that lesson. In 1956, Europeans learned that they could not act independently of Washington. In 2026, they are learning that they cannot rely on Washington’s consent being available, and that the U.S. will act without them, against their stated interests and at their economic expense.

The pattern is the same: Dependence on the U.S. is unsustainable, and autonomous capacity is no longer optional. What has changed is that Europe is now willing to use the financial, economic and military tools it has long possessed in ways it would not have considered before.

The EU’s €90 billion joint-debt loan to Ukraine signals an autonomous European strategic stance. So do discussions of activating the bloc’s anti-coercion trade instrument against U.S. tariffs, France’s nuclear arsenal expansion and offers to “Europeanize” deterrence.

The strategic postures were debated for decades. The Iran war is making them operational.

This is not yet European strategic independence. Europe remains militarily reliant on U.S. air defense, satellite capacity and intelligence.

The closure of the Strait of Hormuz, for example, has forced an uncomfortable energy reckoning with American liquefied natural gas, Russian pipelines, Middle Eastern hydrocarbons and Chinese-dominated renewable supply chains. None of the available paths to energy security run through trusted partners.

France and Germany still disagree on nearly every detail of how integration should proceed. But the political condition for autonomy, a shared European belief that Washington can no longer be trusted to share strategic decision-making, has crystallized in a way that no previous crisis produced.

The post-1945 trans-Atlantic bargain traded U.S. security guarantees for European deference on global strategy. Iraq 2003 strained that bargain. Trump’s first term cracked it, and the Iran war has broken it.

What replaces it will not be a renewed partnership. It will be a parallel relationship between two powers with sometimes overlapping interests and, increasingly, separate strategic horizons.

In 1956, Europe learned how dependent it was on Washington. In 2026, it is learning that dependence is no longer sustainable.

Eleni Lomtatidze, a student in the International Relations Program at the University of Pennsylvania and at SciencesPo Paris, contributed to this story.