Ship traffic through the Strait of Hormuz remains constrained despite an interim U.S.-Iran ceasefire, as Tehran consolidates control over the vital waterway and maintains the infrastructure to impose tolls that legal experts say would violate international maritime law. The provisional framework signed this year gives Iran management authority over the strait while holding the door open to future fee collection after a 60-day negotiating period expires.
Tehran's Expanding Maritime Authority
Iran's lead negotiator and parliament speaker, Mohammad Bagher Qalibaf, told Iranian state media Monday that his country would manage the strait in accordance with international maritime law. But Iran last month established the Persian Gulf Strait Authority specifically to collect money from ships, and officials have said they still expect vessels to register with the new governmental body. The Trump administration imposed sanctions on the authority late last month, with Treasury Secretary Scott Bessent describing Tehran's actions as an attempt to extort global maritime trade.
Maritime tracking data confirmed 131 ships traveled through the strait between Friday and Monday, including 39 crossings on Monday, according to data and analytics company Kpler. Before the U.S. and Israel launched strikes on Iran in late February, about 100 to 130 vessels a day made the journey. The main central route remains mined and closed. Ships have been using the smaller northern route through Iranian waters and the southern route through Omani waters, with many vessels either sticking to Iran's prescribed route or concealing their positions by keeping transponders off.
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 what shipping analysts dubbed a pay-to-pass "tollbooth." Iran demanded in early April the right to collect tolls as a precondition for relinquishing its chokehold on the strait. Tehran and Washington clashed over the waterway again this past weekend when Iran declared it reclosed the strait, citing Israel's latest attacks on Lebanon. The U.S. contested that claim, and maritime data showed dozens of ships passed through on Saturday and Sunday.
The Legal Framework Under Pressure
Collecting tolls in the strait would violate a foundational principle of international maritime trade: freedom of peaceful navigation. The United Nations' Convention on the Law of the Sea, which took effect in 1994, provides ships the right of unimpeded "transit passage" through more than 100 straits worldwide, including the Strait of Hormuz. The treaty only permits fees for man-made waterways such as the Panama Canal and Suez Canal.
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. "You can't impose fees for a ship exercising its right of transit passage," Kraska said. "So the bottom line is, no — fees in this context are just not lawful." He noted that if Iran wants to apply fees universally, "it has to adjust the traffic separation scheme rules, and that can only be done through the member states of the International Maritime Organization."
Neither the U.S. nor Iran has ratified the U.N. convention, but maritime associations argue all nations remain subject to the treaty's provisions. Both countries are members of the International Maritime Organization and parties to the International Convention for the Safety of Life at Sea.
Strategic Uncertainty and Trump's Response
President Donald Trump suggested Saturday the U.S. might impose its own tolls on strait crossings for "services rendered as the Guardian Angel to the countries of the Middle East" if a final deal with Iran is not reached during the 60-day negotiating period. The administration has not provided details on how such charges would be applied. Shipping analysts expressed surprise at how much control 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.
Last week's memorandum of understanding allowed Iran to manage the strait 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. No one country owns the Strait of Hormuz, which borders both Iran and Oman. As part of the provisional framework, Iran said it would conduct demining work within 30 days and remove "technical and military obstacles" to shipping.
Legal experts and maritime associations have stressed that a toll regime would upend decades of international trade precedent. Marcus Baker, global head of marine, cargo and logistics at insurance brokerage Marsh, said the interim deal does not include language for keeping the strait toll-free beyond the negotiating window. "We'll see what the next six weeks brings us," he said. 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.
Why This Matters:
The Strait of Hormuz carries roughly one-fifth of global oil supplies, making Iran's consolidation of management authority over the waterway a strategic shift with consequences far beyond the immediate ceasefire. Tehran's establishment of a toll-collection infrastructure and its history of weaponizing the strait during the recent conflict demonstrate how quickly commercial passage can be held hostage to geopolitical leverage. The provisional framework's silence on long-term toll prohibition leaves open the possibility that Iran will attempt to extract revenue from global maritime trade in violation of international law once the 60-day window closes. Trump's suggestion of counter-tolls reflects the dilemma: rewarding Iran's coercive closure of the strait with management rights creates incentives for future disruption, but contesting that authority without a credible enforcement mechanism risks another round of escalation. The legal precedent is clear, but enforcement depends on political will and naval presence—both of which remain uncertain as negotiations proceed.