Iran is increasingly acting as the gatekeeper of the Strait of Hormuz, selectively allowing ships without US or Israeli links to pass, with traffic collapsing to around 100 vessels since the conflict began, attendees at a Bahrain-based think tank’s geopolitical webinar heard.
During the recent webinar titled ‘Securing the Strait of Hormuz in Wartime: Military Options and Strategic Challenges’ hosted by the International Institute for Strategic Studies (IISS), Lloyd’s List Intelligence senior risk and compliance analyst Bridget Diakun revealed that open source shipping data showed that Iran was selectively letting through vessels without US and Israel links to pass through the Strait.
“Traffic is still moving through the Strait of Hormuz,” Ms Diakun noted.
“There has never been a complete closure. Since the start of the month, just over 100 ships have passed through.
“For comparison, in the same period last year there were nearly 1,900, so traffic is down very sharply. We still see activity across sectors: bulk carriers, tankers and container ships are all still moving.”
Iran-linked vessels make up 24 per cent of the transits, followed by Greece (18pc) and China (10pc).
Nearly 60pc of permitted transits have an Iranian nexus, either through trade, ownership or flag.
The conflict has also created a ‘Tehran-approved’ corridor, according to Ms Diakun, where all but one vessel detoured around Iran’s Larak Island.
“In recent days we’ve seen vessels linked to the Indian and Pakistani governments transiting, and there are signs that China may push for more state-linked vessels to go through as well,” Ms Diakun added.
“We can see at least one China-linked VLCC (Very Large Crude Carrier) heading east at full speed; we’re watching to see if it actually transits.
“Overall, there is little evidence that anyone has a guaranteed ‘free pass’ through the Strait. If there were solid, negotiated arrangements, we’d expect many more ships to move.
“The fact that Greek vessels are getting through suggests the criteria is not strictly limited to a small set of ‘friendly’ governments. Broadly, Iran seems to be allowing anything without a US or Israeli nexus.
“They’re casting a wide net in checking this. We understand they ask for detailed information on historical ownership, previous ports of call and background data.
“It looks similar to the Houthi pattern in the Red Sea, where US and Israel‑linked vessels are the primary targets.”
IISS–Middle East executive director Air Marshal (Retd) Martin ‘Sammy’ Sampson noted that any military effort to secure the Strait would fundamentally change the current conflict against Iran, pushing US forces into operational overstretch, and carrying heavy strategic costs even if it succeeds tactically.
He noted that the battlefield has shifted in the past couple of weeks as US, Israeli and Iranian actions have created a fluid, actively managed campaign rather than a pre‑planned, narrowly scoped one.
According to him, the US force posture does not seem to have been originally configured to secure Hormuz.
There were no dedicated mine‑countermeasure vessels, only one carrier strike group, and forces were positioned for a largely air‑centric, standoff campaign, not for concentrated maritime operations in the Strait.
The later arrival of additional assets (USS Tripoli, a Marine Expeditionary Unit, carrier groups and THAAD systems) represents a strategic repositioning, not the activation of a pre‑planned reserve.
The conflict so far has effectively been a joint and combined air campaign.
To secure the Strait, Mr Sampson noted that it must become a truly multi‑domain, joint and combined campaign, integrating maritime forces, ground elements, allies and civilian actors such as the shipping industry, which raises complex command‑and‑control and operational security issues.
In addition, the current focus on degrading Iran’s wider defence, missile and nuclear capabilities does not naturally align with a narrow Hormuz security mission.
Mr Sampson warned that focusing on the Strait would force the US to concentrate forces in a small, predictable area, reversing its prior policy of dispersal.
This could create a ‘target‑rich environment’ for Iran, highlighting not just immediate risks like casualties and ship losses but also ‘operational stretch’.
This would include extended deployments, deferred maintenance, equipment wear and tear, strain on the defence industrial base and on space assets, and human fatigue.
In parallel with preventing the reconstitution of Iranian forces, Mr Sampson noted that US military planners must think about what would go into rebuilding the armed forces after the campaign.
According to IISS senior fellow for naval forces and maritime security Nick Childs, senior US commanders have been cautious, signalling that Washington is not yet ready to launch a full‑blown operation to secure the Strait, and is instead trying first to destroy Iranian anti‑ship capabilities with strikes on missile silos, bunkers and coastal infrastructure around the waterway.
While Gulf states have been investing in modern warships, their ability to protect themselves under sustained threats or provide reliable naval escorts is limited.
Mine countermeasure capabilities in the region are also thin, and Western mine countermeasure forces are few and vulnerable, requiring protection themselves.
“Just the threat of mining is going to put a hesitancy in to ship operators, because fundamentally, as has been said on multiple occasions, mines have two warheads,” Mr Child added.
“One is a high explosive warhead, and either the other one is a psychological one, and just the possibility that there might be a mining threat may be enough to maintain a stranglehold on shipping.”
Also speaking during the webinar, IISS research fellow for defence and military analysis Sascha Bruchmann noted that bringing in US Marines to raid or secure key Iranian‑controlled islands and deploy counter‑drone systems could reduce threats to shipping, but Iran’s residual drone and small‑boat capabilities could pose a persistent, guerrilla‑style maritime risk.
naman@gdnmedia.bh
*What is it?
The Strait of Hormuz lies between Oman and Iran and links the Gulf north of it with the Gulf of Oman to the south and the Arabian Sea beyond.
It is 33km wide at its narrowest point, with the shipping lane just 3km wide in either direction.
*Why does it matter?
About 20pc of the world’s total oil consumption passes through the Strait.
More than 20 million barrels of crude, condensate and fuels passed through the Strait daily last year on average.
Saudi Arabia, Iran, the UAE, Kuwait and Iraq export most of their crude via the strait, mainly to Asia.
Qatar, among the world’s biggest liquefied natural gas (LNG) exporters, sends almost all of its LNG through the strait.
The US Fifth Fleet, based in Bahrain, is tasked with protecting commercial shipping in the area.
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