For two months, under a discreet arrangement with the U.S. Navy, commercial tankers disabled their transponders to evade detection by Iran while navigating the volatile Strait of Hormuz, transporting oil and gas to global markets. The military provided aerial protection in case of Iranian aggression, with naval officers guiding vessels via radio to stay close to Oman’s coastline, opposite Iran’s shores. This strategy facilitated a gradual rise in traffic through the strait from May to June during an uneasy cease-fire.
However, the framework agreement signed by President Trump with Iran last month effectively ended this initiative. The deal granted Tehran official authority over the strait and contained ambiguous language in critical clauses. Trump hailed the June 14 agreement as the reopening of the strait, declaring on social media, “Ships of the World, start your engines. Let the oil flow!” Yet critics argue it formalized Iran’s de facto control, which Iranian officials have repeatedly asserted since the war began.
Iran’s missile and drone assaults on commercial vessels soon paralyzed the strait following the U.S.-Israeli military campaign. Weeks after the informal April cease-fire, some tankers adopted a southern route, farther from Iran’s coast. Recent attacks on that corridor by Iranian forces aim to compel ships to navigate the northern route through Iranian territorial waters, where Tehran seeks to impose tolls or fees.
The U.S. military confirmed Iran targeted three ships on Tuesday, prompting retaliatory airstrikes by Trump. Escalating tensions emerged when Iran’s Navy announced it had engaged another vessel and temporarily closed the strait, citing ongoing U.S. regional interference. In response, U.S. Central Command struck approximately 140 Iranian military targets, bringing the total of American strikes in the past week to 310.
Former diplomats and analysts attribute the latest crisis to the June agreement’s shortcomings. Trump’s push to reopen the strait, aimed at easing inflation and global energy costs, led to ending the U.S. naval blockade of Iranian ports and allowing 60 days of Iranian oil sales. Critics, however, condemned the deal’s vagueness, particularly a clause stating Iran would use “best efforts” to ensure safe passage.
“No one should be surprised that Iran interprets this as granting them a permanent role in controlling the strait,” said Michael Ratney, former U.S. ambassador to Saudi Arabia. “Their control provides significant leverage, and they seem prepared to risk renewed conflict to maintain it.”
Vice President JD Vance emphasized at a June 18 press conference that Trump’s demands regarding the strait would be enshrined in future agreements, asserting, “We have all the cards.” The strait’s contested status presents a dilemma for shipping firms: opt for the southern route near Oman and risk Iranian attacks, or traverse the northern corridor, incurring fees that bolster Iran’s authority claims.
A Controversial Agreement
For nearly six decades, commercial ships used a U.N.-established route through the Strait of Hormuz. Iran supported the route in 1968 without asserting control, even as it lay within Iranian waters. Post-1979 revolution leaders renounced the U.N. accord but rarely disrupted shipping until February 28, when U.S. and Israeli strikes triggered Iran’s naval counterattacks and mine-laying, halting traffic. Only ships paying substantial fees secured safe passage.
Detractors argue Trump’s June agreement legitimized Iran’s dominance. The 14-point document acknowledges Iranian influence in the strait, banning fees for just 60 days during ongoing talks. It lacks explicit guarantees ensuring vessel safety across the entire strait. Iranian officials now cite the agreement as justification for mandating the northern route, a stance echoed by Dennis Ross, a veteran Middle East negotiator: “You were reopening the strait—but only on the condition that Iran was fully in control.”
During the war’s peak, some operators opted for the Iranian-guaranteed northern route, paying up to $2 million per ship. Iran requires transit permission through the Persian Gulf Strait Authority, created in May. While Tehran labeled fees as safety and environmental services, experts argue this mirrors prohibited tolls under the U.N. Convention on the Law of the Sea—a treaty Iran signed but never ratified. The U.S., which has also not ratified the convention, rejects Iran’s demands, instead establishing the southern route in May.
Trump declared the route “totally safe, secure, and pristine” post-agreement. However, escalating military posturing between Iran and the U.S. risks heightened peril for shipping firms, warned Dan Alamariu of Alpine Macro. Iran faces economic strain but may tolerate further pressure. Trump reinstated the Iranian oil ban but has yet to reinstate the naval blockade, leaving open the question of which economy—Tehran’s or the global one—will falter first.