Maritime risk in the Strait of Hormuz has surged back to "severe" as shipping companies, regulators and insurers warn that attacks on tankers and rising war‑risk costs through the key shipping route have once again turned unsustainable.
The US Navy‑led Joint Maritime Information Center (JMIC) this week raised its advisory level for transiting Hormuz from "substantial" to "severe", the highest category, citing a likelihood of "deliberate hostile action" under current conditions. It is the first time since mid‑June that the strait has been classified at that level.
The impact is already visible on the water. Open data on Thursday showed only two tankers had passed through Hormuz in the early hours: a sanctions‑hit crude carrier that loaded at Iran’s Kharg Island, and the Marshall Islands‑flagged chemical tanker Well Sail.
Conflict‑monitoring group ACLED told The New Arab that, in its assessment, this is not a brief pause but a persistent threat.
"Risk will remain high for all ships transiting the Strait of Hormuz for the foreseeable future and as long as there is no bilateral agreement between the US and Iran to formally agree on the status of maritime shipping through the strait," Sherwan Hindreen Ali, ACLED’s Middle East Research Manager, said.
Analysts say the collapse in transits reflects how shipowners are reading the risk, much more than statements announced in Washington or Tehran, and marks a sharp reversal from the partial reopening of the strait after the recent US-Iran memorandum of understanding.
Drawing on its incident database, ACLED notes that ships have been attacked in both international and national waters across the Gulf since the US-Israel war with Iran began on 28 February, including during the current post‑ceasefire period.
"No authority has been able to militarily neutralize the Iranian security threat to shipping so far," Ali added. In his view, a diplomatic arrangement that convinces Tehran to cease attacks is more plausible than trying to secure the route by force alone – but such a deal is unlikely unless it is folded into a broader agreement to end the war and provide some sanctions relief for Iran.
The immediate backdrop to the new risk assessment is a cluster of attacks on commercial vessels earlier this week.
On Tuesday, Iranian forces fired on three ships in Oman’s territorial waters near Hormuz, including a Qatari gas carrier and a Saudi oil tanker, in the first such incidents since signing of the MoU. Those strikes, and Washington’s decision to hit more than 160 Iranian targets in response, have shattered any sense that the truce had removed merchant shipping from the firing line.
Insurers pull back, costs surge
War‑risk insurers and regulators are responding in parallel. Specialists have advised some shipowners to pause voyages through Hormuz after the latest tanker incidents , while others review war‑risk terms for vessels in the Gulf.
War‑risk cover is normally sold on a seven‑day basis and repriced every 24 to 48 hours, and even small shifts at current levels translate into hundreds of thousands of dollars in extra daily costs for large tankers.
Industry sources told Reuters this week that rates for ships operating inside the Gulf have moved towards roughly three percent of vessel value, up from around two percent late last week. For owners already facing elevated premiums since the start of the war, that jump makes transiting the region significantly more expensive and further strengthens the case for delaying and, ultimately, diverting voyages.
Likewise, the UN’s International Maritime Organization (IMO) has warned that sailing through Hormuz should be avoided "as long as the safety and security of crews cannot be assured".
The organisation’s secretary‑general, Arsenio Dominguez, has described the continued high cost of war‑risk insurance as a major concern "compounding the strain on shipowners and operators", and has urged governments with leverage over insurance and reinsurance markets to work with underwriters so that premiums reflect current conditions rather than the peak of the crisis earlier in the war.
Oil sanctions and Iran’s response
The renewed disruption to the Hormuz strait is already feeding back into energy markets and sanctions policy. On Tuesday, the US Treasury’s Office of Foreign Assets Control revoked Iran’s temporary authorisation to sell oil under a limited sanctions waiver and replaced it with a short wind‑down licence, closing off a channel that had allowed some Iranian exports in recent weeks.
Brent crude prices have, as a result, moved back above $76 per barrel this week, driven by concerns over Iranian supply and the broader security of Gulf shipments that depend on Hormuz.
Iran is framing the disruption as being the result of US actions. The Revolutionary Guard navy says that attacks on Iranian territory and foreign efforts to redirect shipping away from routes under Tehran’s supervision are to blame for interrupting the strait’s reopening.
It claims that transit under Iranian oversight has recovered to roughly half of pre‑war levels, and argues that outside interference is preventing a wider resumption of traffic.
Iran’s chief negotiator has meanwhile insisted that the Strait of Hormuz will only stay open under "Iranian arrangements" after the latest exchange of strikes between Tehran and Washington.
In a post on X, parliamentary speaker Mohammad Bagher Ghalibaf accused the United States of "bullying" and breaking its promises, warning: "If you strike, you will be struck" – a formulation that explicitly links US military actions to Iran’s willingness to target shipping.