Iran-US Crisis — 2026-04-18

Iran reimposes Strait of Hormuz closure; IRGC gunboats fire on commercial shipping as Trump convenes situation room

The IRGC declared the Strait of Hormuz closed again Saturday morning in response to the ongoing US naval blockade of Iranian ports, and within hours gunboats fired on at least two Indian-flagged vessels, the cargo ship JAG ARNAV and VLCC SANMAR HERALD, while a container ship 25 nautical miles off Oman took an unidentified projectile. UKMTO confirmed three separate incidents. President Trump convened a White House situation room meeting Saturday morning, said Iran got cute trying to close the strait, and reaffirmed that the US blockade will remain in full force until the deal is 100 percent complete. A Paris-hosted summit with representatives from 49 countries endorsed continued pressure even as France signaled discomfort with the targeted blockade framing.

Analysis
With UKMTO-confirmed firing across three separate incidents, the reclosure shifts from political theater to operational emergency on asymmetric provocation logic: the blockade/counter-blockade now rewards whichever actor is most willing to absorb the first casualty, and we assess very likely within 72 hours that one side escalates materially, either a US strike on IRGC assets operating outside the strait or an Iranian incident that kills a mariner. Trump's public "got a little cute" framing forecloses the quiet diplomatic corridor before the April 21 ceasefire expiration. The gunfire may instead be primarily domestic, constraining Pezeshkian's negotiating hand rather than genuine maritime denial, in which case reopening comes quickly and no mariner dies; incident tempo over the next 48 hours will arbitrate.

5 sources

Scoop: Trump convenes Iran situation room meeting amid renewed Hormuz crisis - Axios
Iran closes Strait of Hormuz again over US blockade of its ports - Al Jazeera
Iranian gunboats fire on Indian-flagged ships in Strait of Hormuz - Naval Today
Vessels report being hit by gunfire as Iran says Strait of Hormuz shut again - Military Times
Iran blocks Strait of Hormuz, fires on commercial ships - UPI