Iran’s Islamic Revolutionary Guard Corps declared the Strait of Hormuz shut on Saturday in response to Israeli strikes in Lebanon, triggering an immediate plunge in recorded transits. Maritime intelligence firm Windward tracked just 12 vessels crossing on Sunday, down from 35 the previous day, while Kpler data showed only five ships passed. By Monday afternoon, however, traffic had partially recovered: Kpler recorded 26 commodity-ship transits by 15:30 GMT, and AXSMarine data indicated the daily pace could exceed the post-memorandum highs seen late last week.

The renewed closure announcement was accompanied by rules from Iran’s Persian Gulf Strait Authority requiring vessels to seek permission, disclose ownership and cargo details, and submit to potential penalties or future insurance fees. British defence analyst Michael Clarke described the demands as illegal under the UNCLOS transit-passage doctrine, viewing them as an attempt to normalise Iranian administrative control over the waterway. Behind the legal manoeuvring, analysts in London note, lies a long-term revenue objective: J.P. Morgan’s annual energy paper estimates tolls alone could yield $70–90bn. A US-Iran deconfliction line, brokered with Qatari and Pakistani mediation, now exists to prevent miscalculation, yet Tehran continues to tie the strait’s status to the Lebanon front, using oil-supply anxiety as leverage against Israeli operations.

Physical flows reflected the contradictory signals. Four QatarEnergy LNG tankers entered the strait via the Iranian route on Monday for the first time since the war began on 28 February, while three sanctioned Iranian very large crude carriers—Elva, Virgo and Vigor—loaded weeks ago at Kharg Island were exiting openly, a posture shift that Israeli firm Windward linked to reduced concealment needs after the 17 June US-Iran MoU. Abu Dhabi’s ADNOC and Kuwait Petroleum Corporation have issued tenders allowing loading from either side of the strait, and two ADNOC LNG carriers completed “dark” voyages to India. US Central Command insisted 55 merchant ships transited on Saturday, a figure supply-chain expert Behrouz Bakhtiari in Canada suggested may include vessels running with transponders off, while Iran’s state oil company claimed over 25 million barrels of Iranian crude had crossed the virtual blockade line in the preceding week. Brent crude slipped 0.9 percent to below $80 a barrel on Monday morning in Asia, and major Asian equity indices rose, suggesting markets were not yet pricing a full closure.

US and Iranian negotiators met in Switzerland on Sunday to prevent the Lebanon escalation from derailing the 60-day ceasefire extension. Both sides discussed safe-passage mechanisms, and Iran’s foreign ministry spokesman confirmed a communication channel had been set up. The next factual test is whether the fragile diplomatic track can hold through the coming week, with strait traffic levels and the durability of the deconfliction line serving as real-time barometers of progress toward a permanent peace deal.