Key facts
- Oil tanker traffic through the Strait of Hormuz has fallen steeply following U.S. airstrikes and Iranian retaliation.
- Just 23 tankers and cargo ships crossed the critical waterway on Wednesday, down from 47 a week prior.
- Three ships were struck this week in Omani waters, prompting Iran to reiterate its demand that all traffic use its approved routes.
- Iran is discussing the situation with Oman and Turkey via diplomatic channels to prevent escalation.
- A deal signed June 17 included steps to reopen the strait, but Iran's insistence on controlling passage and the US revoking a sanctions-easing license have complicated matters.
Traffic through the Strait of Hormuz has fallen steeply following a series of tit-for-tat strikes by the U.S. and Iran, with just 23 tankers and cargo ships crossing the critical Gulf waterway on Wednesday, down from 47 a week prior. The incidents follow an attack on three tankers earlier this week, which were using a U.S.-recommended route through Omani waters. Iran has repeatedly stated that the only "safe" route is a separate route through its own waters.
For decades, vessels have been granted free passage through the strait, which handles more than a fifth of the world's oil and gas supplies, as well as fertilizer shipments and other vital goods. Before the recent conflict, an average of 138 ships transited the strait daily. Following initial U.S. and Israeli strikes on Iran on February 28, traffic dropped to a handful of ships per day, with Iran effectively closing the strait by attacking ships and laying mines, and the U.S. responding with a blockade on Iranian ports.
A deal signed on June 17 aimed to end the conflict and included provisions for reopening the strait, with Washington agreeing to lift its naval blockade and ease sanctions on Iranian oil exports. Following this agreement, traffic levels initially increased, peaking at 72 ships on June 24. However, Iran has insisted on its right to control passage and impose fees, a stance opposed by the U.S. and its allies who advocate for free and open passage.
Iran subsequently established lanes near its coast, declaring them the only safe route. The Joint Maritime Information Center (JMIC) recommended an alternative route through Omani waters. This Omani route saw a peak of 28 vessels on June 25, surpassing the Iranian route. However, on June 25 and 27, two ships in Omani waters were struck, leading Iran to warn all vessels to use its approved routes. U.S. President Donald Trump accused Iran of a "foolish violation," and the U.S. military conducted strikes on Iranian targets. Iran, in turn, accused the U.S. of violating the interim deal and struck targets linked to American forces.
The recent attacks on three ships have caused a significant slump in traffic via the Omani route. No ships used it on Wednesday, down from three the previous day, and averaging about 10 daily in the week prior. Martin Kelly, senior intelligence analyst at EOS Risk Group, anticipates a familiar pattern of back-and-forth strikes until another agreement is reached.
The June 17 memorandum of understanding (MOU) committed Iran to "best efforts for the safe passage of commercial vessels with no charge for 60 days" and to "conduct dialogue with the Sultanate of Oman to define the future administration and maritime services in the Strait of Hormuz." Iran interprets these clauses as granting it control, while critics note the lack of long-term commitment to free passage. Jennifer Parker, a maritime security expert, stated the MOU does not permit Iran to attack civilian shipping in Omani waters. Concerns over sea mines laid by Iran also contribute to reduced traffic levels.
Iran's Revolutionary Guard Corps asserted that "foreign powers have no claim to this land or to the Strait of Hormuz" and warned that "any interference in determining shipping routes" would provoke a "crushing response." President Trump declared the MOU "over" but indicated negotiations could continue. Iran also accused the U.S. of violating the agreement by revoking a Treasury license that had eased sanctions on its oil exports. Parker noted that neither economic relief nor military threats have altered Iran's behavior, highlighting the challenge of balancing "the carrot and the stick."