Two large Chinese-linked container ships made an abrupt U-turn near the Strait of Hormuz on Friday as Iran tightens its grip on one of the key passages for global shipping. Ship-tracking data showed the CSCL Indian Ocean and CSCL Arctic Ocean, both linked to China’s state-owned COSCO Shipping, attempted to leave the Gulf in the early hours before turning back close to Iranian waters. The move came despite Tehran’s recent assurances that vessels from “friendly nations”, including China, would be allowed to pass.Interestingly, Iran’s foreign minister Abbas Araghchi had stated just a day earlier that Tehran would permit safe passage through the Strait of Hormuz for ships from five “friendly” nations: China, Russia, India, Iraq, and Pakistan.
According to ship-tracking data, the two vessels moved towards the narrow Strait at around 0350 GMT before reversing course near Iran’s Larak and Qeshm islands.
- This marked the first known attempt by a major global shipping operator to exit the Gulf since the war began
- Both ships had been stranded in the region for weeks
- Analysts cited by WSJ described the reversal as “unusual” given prior signals that Chinese-linked vessels might be allowed through
Rebecca Gerdes, an analyst at Kpler, told Reuters that the episode showed that “safe passage could not be guaranteed”, despite diplomatic messaging from Tehran.Bloomberg reported that the vessels had earlier altered their tracking signals to indicate Chinese ownership and crew, a tactic previously used by ships seeking to avoid confrontation in the waterway.
Iran tightens control over key chokepoint
The Strait of Hormuz, through which roughly a fifth of the world’s oil and gas normally flows, has effectively been brought under Iranian control since the conflict escalated.
- Tehran has combined military threats with selective permissions to regulate movement
- Iranian Revolutionary Guard forces have reportedly turned back multiple vessels
- Shipping firms now face a patchwork system of approvals and restrictions
Iran has also indicated that vessels linked to countries seen as backing the United States or Israel could be denied passage altogether. On Friday, Iranian forces said they had warned off three container ships of different nationalities attempting to cross.
‘Toll booth’ system emerges
Industry data and maritime reports suggest Iran is increasingly operating a de facto approval system for ships seeking transit.
- Vessels may be required to submit cargo, ownership and crew details for clearance
- Some ships have reportedly paid fees — in Chinese yuan — to secure passage
- Approved vessels are sometimes escorted through Iranian-controlled routes
Shipping intelligence firms have described this as a “toll booth” model, effectively allowing Tehran to control who moves through the strait and on what terms.At least some vessels, particularly those carrying goods destined for Iran, have been allowed through in recent days, while others remain stuck.
Traffic collapses, risks surge
The broader impact on global shipping has been severe.
- Traffic through the strait has fallen by up to 90–95% since early March
- Only a fraction of normal daily vessel movements are currently taking place
- At least 20,000 seafarers are believed to be stranded in the Gulf region
Security risks have also intensified. Maritime agencies report multiple attacks on commercial vessels since the conflict began, with casualties among crew members.Many ships are now switching off tracking systems while navigating the region, reflecting heightened fears of targeting.
Energy markets and geopolitics
The disruption has sent shockwaves through global energy markets, with exports of crude oil and liquefied natural gas from Gulf producers sharply curtailed.Despite the broader slowdown, Iranian oil shipments — particularly to smaller Chinese refineries — appear to have continued, suggesting Tehran is leveraging its control to maintain key export flows.Meanwhile, tensions remain high. The United States and Iran are exchanging proposals through intermediaries, but the situation on the ground — and at sea — continues to deteriorate.