Ship traffic through the Strait of Hormuz remains fragile and uncertain following an interim ceasefire between Iran and the United States, with Tehran's insistence on managing the vital waterway and collecting tolls threatening both the flow of global commerce and negotiations for a lasting peace agreement. The dispute over control of the strait — through which roughly a fifth of the world's oil once passed — has left shipping companies navigating not only physical hazards but legal ambiguity that could upend decades of international maritime law.
Iran's lead negotiator, Mohammad Bagher Qalibaf, who is also the speaker of the Iranian parliament, told Iranian state media Monday that the Strait of Hormuz will be managed by Iran and would follow international laws. But legal experts and maritime associations have repeatedly stressed that a toll regime would violate the principle of freedom of peaceful navigation codified by the United Nations' Convention on the Law of the Sea, which took effect in 1994 and provides ships the right of unimpeded "transit passage" through more than 100 straits worldwide, including the Strait of Hormuz.
The Toll Dispute and Its Human Cost
Tehran and Washington clashed over the Strait of Hormuz again this past weekend. Citing Israel's latest attacks on Lebanon, Iran declared that it reclosed the strait. The U.S. was quick to contest that. Maritime tracking data showed that dozens of ships passed through on Saturday and Sunday, though far fewer than the daily average before the war. Data and analytics company Kpler said its tracking confirmed 131 ships traveled through the strait between Friday and Monday, including 39 crossings on Monday. In contrast, about 100 to 130 vessels a day made the journey before the U.S. and Israel launched strikes on Iran in late February, and Tehran responded with its own attacks and effective closure of the waterway.
The disruption to global oil supplies has fueled inflation worldwide, with the cost of energy and commodities rising sharply. If the U.S. and Iran cement a final deal, analysts say it could take months for the flow of oil, natural gas, fertilizer and other commodities to return to prewar levels. The economic consequences extend far beyond shipping companies to consumers facing higher prices for fuel, food, and manufactured goods.
President Donald Trump suggested the U.S. might impose its own tolls on strait crossings if a final deal with Iran was not reached during the countries' 60-day negotiating period. Passage was free before the war, but Iran last month established a new governmental authority to collect money from ships and has said it still expects vessels to register with the Persian Gulf Strait Authority. Although the Trump administration imposed sanctions on the Persian Gulf Strait Authority late last month to oppose what Treasury Secretary Scott Bessent described as Tehran's attempt to extort global maritime trade, the president on Saturday suggested the U.S. could impose its own tolls for "services rendered as the Guardian Angel to the countries of the Middle East." The administration has not provided details on how the U.S. would apply any charges on ships if talks with Iran do not yield a completed agreement.
International Law and Maritime Precedent
No one country owns the Strait of Hormuz, which borders both Iran and Oman. Last week's memorandum of understanding allowed Iran to manage the strait for now while holding discussions with Oman and six other Gulf states "to define the future administration and maritime services" of the waterway. Iran agreed not to charge transiting vessels tolls for 60 days. Oman is among the more than 170 countries that have ratified the U.N. convention, but the U.S. and Iran are not. Maritime associations have argued that all nations remain subject to the treaty's provisions.
James Kraska, a U.S. Naval War College professor of international maritime law and visiting professor at Harvard Law School, said fees can only be applied at established ports of entry or for services specifically requested by a ship, such as specialized navigation aid through hazardous areas. "If Iran wants to apply those to everybody, then it has to adjust the traffic separation scheme rules, and that can only be done through the member states of the International Maritime Organization," he said. "You can't impose fees for a ship exercising its right of transit passage. So the bottom line is, no — fees in this context are just not lawful."
The treaty only applies to natural waterways, so authorities can charge fees for ships to traverse man-made waterways such as the Panama Canal and the Suez Canal. Countries sometimes have joined forces to share the costs of maintaining a strait, Kraska noted. For example, Indonesia, Malaysia and Singapore worked with the International Maritime Organization and later other countries to develop such an agreement for the Strait of Malacca, but it involved negotiated contributions from the states using the passage, not fees on individual ships.
Ongoing Risks to Shipping
The main central route of the Strait of Hormuz is still mined and remains closed. Ships have been using the smaller northern route, which goes through Iranian waters, and the southern route, which goes through Omani waters. But "caution is still clear" in the many vessels either sticking to Iran's prescribed route or trying to conceal their positions and identities by keeping their transponders off, Kpler said. As part of the provisional Iran-U.S. framework, Iran said it would conduct demining work within 30 days and remove "technical and military obstacles" to shipping.
Early in the war, Iran threatened to attack ships that tried to use the Strait of Hormuz without its approval and began vetting vessels in a pay-to-pass scheme that shipping analysts dubbed the "tollbooth." Iran also demanded in early April the right to collect tolls as a precondition for relinquishing its chokehold on the strait. Shipping analysts have expressed surprise at how much control over the strait the initial agreement gave Iran. "Almost all the power goes into Iran to determine the arrangements going forward in the future. This is what we really need clarity on," said Philip Belcher, marine director of Intertanko, a trade group for independent tanker owners, said Thursday.
Marcus Baker, the global head of marine, cargo and logistics at insurance brokerage and risk management company Marsh, said conditions in the Strait of Hormuz have escalated or deteriorated quickly over the course of the war. While the outlook for shipping has improved since the U.S. and Iran pledged to extend their ceasefire, "there is a degree of nervousness around the situation," he said. "As far as the insurance position is concerned, there's a good deal of support for ship owners that are trying to move out" during this period, but the interim deal between Iran and the U.S. does not include language for keeping the strait toll-free beyond the negotiating window, Baker said. "We'll see what the next six weeks brings us," he said.
Why This Matters:
The dispute over the Strait of Hormuz governance reveals how military conflict can destabilize not only regional security but the legal frameworks that govern global commerce. The principle of free passage through international straits has underpinned maritime trade for decades, and any precedent allowing unilateral toll collection could embolden other nations to assert similar claims over critical waterways. The economic consequences extend to ordinary consumers worldwide who face higher energy and food costs as long as shipping remains disrupted. The fragility of the current ceasefire and the absence of clear language protecting toll-free passage beyond the 60-day negotiating window leave global trade vulnerable to renewed escalation. A durable peace agreement must address not only military security but the legal architecture that allows commerce to flow freely — a necessity for both regional stability and the global economy that depends on predictable access to the world's most vital oil chokepoint.