# Taking the Pulse: Is European Diplomacy on Iran Outdated? 

At present, any effort to mitigate the war’s damage to European interests must focus on keeping Trump on a path to peace, somehow.

June 18, 2026 • Commentary 

By [Justin Logan](https://www.cato.org/people/justin-logan) 

This article appeared in [*Carnegie Europe*](https://carnegieendowment.org/) on June 18, 2026.

U.S. President Donald Trump’s superpower is revealing uncomfortable, long-avoided truths. During the negotiations that led up to and produced the JCPOA, the French delegation was often more hawkish and demanding than the Americans. The question never asked was what the French would do if a deal satisfied Washington but not Paris. Could they lead a sanctions coalition against Iran without the United States at the helm? Could they launch a strike on Iranian nuclear facilities? The 2015 deal was signed, of course, and those questions receded.

But today, Trump has revealed that similar questions loom large. Europe did not want this war, but could not stop it. The offer to help clear the Strait of Hormuz hinges on a permissive operating environment provided by both the United States and Iran, meaning the service itself is of limited value. The sanctions question is somewhat more interesting: It is quite possible to envision Washington wanting to lift sanctions and some European capitals not wanting to. What happens then?

Europe has a limited ability to shape outcomes in the Middle East. At present, any effort to mitigate the war’s damage to European interests must focus on keeping Trump on a path to peace, somehow.

##### About the Author 

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##### [Justin Logan](/people/justin-logan)

Director of Defense and Foreign Policy Studies, Cato Institute

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