Days after U.S. and Israeli strikes on Iran began on Feb. 28, 2026, Spanish Prime Minister Pedro Sánchez denied American forces the use of the Naval Station Rota and the Morón Air Base – installations that had hosted U.S. troops for more than 70 years.

“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 let U.S. bombers refuel 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........

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