A toll at the Strait of Hormuz would be a historical violation of international law explains a specialist.

The question of tolls in the Strait of Hormuz will be at the center of Iranian-American negotiations opening on April 11 in Pakistan. Iran aims to formalize the principle, but according to Sylvain Domergue, a geography professor at Sciences Po Bordeaux, “international law is not dead” and the freedom of navigation has a bright future ahead.

France: Do we know if a toll has indeed been implemented in the Strait of Hormuz?

Sylvain Domergue, geography professor at Sciences Po Bordeaux, author of Geopolitics of Maritime Spaces: It’s difficult to say, even though we know that at least three ships in recent weeks have paid a toll to Iran, in a form of extortion. The Iranians would like to institutionalize this toll principle. If so, it would be a historical violation of international law. The principle of free navigation in straits and seas, which prohibits any toll in international straits, dates back to the 17th century. It was further validated by numerous international treaties in the 19th and 20th centuries, and by the Montego Bay Convention [adopted by the UN in 1994]. Even if Iran and the United States have not ratified this convention, they are obligated to respect it since almost all countries on the planet apply it.

Do we have an idea of the amount that may have been paid, especially by the French container ship from CMA CGM that passed a week ago?

Iran talks about 1 to 2 million dollars per ship passing, particularly oil tankers. However, it seems that several of the passing ships did not pay. Either Iran’s partners, the Iranian ghost fleet, the Chinese, or the Indians with whom Iran has specific agreements. But it is unclear if CMA CGM paid. One can imagine a political trade-off due to France’s relatively neutral position in the conflict, a sort of favor in return. There are various rumors about the toll amounts, talking about millions, hundreds of millions, or billions. Iran deliberately maintains this ambiguity, sending various, contradictory, and often maximalist signals to the international public opinion. In the context of negotiations in Pakistan, this is a posture, a way to create tension and pressure on negotiators. But I would be very surprised if an official toll system is implemented.

“We hear all sorts of amounts regarding these tolls. We talk about millions, hundreds of millions, billions… Iran deliberately maintains this ambiguity.”

Donald Trump said on April 9, 2026 that the idea of a toll is not necessarily bad. Should we be concerned about this in the context of the peace negotiations that are set to begin?

Today, he says the opposite, but we know the character, it’s part of the package. In my opinion, it’s a bluff, a way to tell the Iranians ‘you want to implement a toll, fine, we’ll take half of it’. Let me tell you that practically, it’s unfeasible. It’s certainly also a way to pressure China, the main beneficiary of maritime traffic in the Persian Gulf, to get involved and push the Iranians to abandon this idea. But international law is not dead and not about to die. There’s a principle of jurisprudence. If you apply a toll in the Strait of Hormuz, what prevents tomorrow Singapore, Denmark, Russia, Spain, or even France and England from imposing passage fees on the straits that concern them? That’s why I am highly skeptical about the idea of implementing this toll, because of this principle of jurisprudential retaliation.