Ship movements through the Strait of Hormuz have fallen sharply following a series of tit-for-tat strikes between the US and Iran after three tankers were attacked earlier this week. Maritime intelligence firm Kpler reported just 23 tankers and cargo vessels transited the waterway on Wednesday, down from 47 the previous week.
The three struck vessels were using a US-recommended southerly route through Omani waters. Iran has repeatedly insisted that the only safe passage is a separate set of lanes close to its own coast. For decades, vessels have enjoyed virtually free passage through the strait, which carries more than a fifth of the world’s oil and gas, as well as fertiliser and other essential goods.
Before the recent conflict, the Joint Maritime Information Center (JMIC), a multinational maritime group that includes the US, said an average of around 138 ships crossed the strait each day. After the US and Israel launched strikes on Iran on 28 February, daily transits fell to only a handful as Iran attacked ships attempting to cross and laid mines, and the US imposed a blockade on shipping to and from Iranian ports.
A ceasefire agreement signed on 17 June included measures to reopen the strait. Washington agreed to lift its naval blockade and ease sanctions on Iranian oil exports, and traffic initially rose, peaking at 72 transits on 24 June.
During negotiations Iran pushed to assert control over movement through the strait and to impose fees on passing ships, a position opposed by the US, Gulf states, and many European and Asian governments, who say passage must return to being free and open.
After the ceasefire, Iran established a system of northern lanes near its coast and insisted commercial vessels use them, with its military command saying only its route was safe. The JMIC instead recommended a southerly route through Omani waters; Kpler recorded traffic on that Omani route peaking at 28 transits on 25 June.
On 25 and 27 June two ships in Omani waters were struck, prompting Iran to warn vessels to use its approved lanes. The US responded with strikes on Iranian targets after President Donald Trump called Iran’s actions a “foolish violation” of the truce; Iran said the US had breached the interim deal and said it had struck targets linked to American forces. Transit via the Omani route fell sharply after those incidents and has continued at a lower level than before.
