A senior Iranian security official warned that any US' seizure of Iranian oil cargoes would trigger proportionate retaliation against US-linked shipping, energy, insurance and financial interests in the Persian Gulf, Nour News reports

Threats of this kind out of Tehran follow a familiar script: they are issued through semi-official channels, framed as proportionate and conditional, and calibrated to raise the cost of enforcement without committing to escalation. The precedent pattern in past tanker-seizure standoffs is a sequence of rhetorical warning, sporadic harassment or detention of vessels linked to the counterparty or its allies, and eventual de-escalation through back channels, with outright closure of the Strait of Hormuz threatened often and never executed. The transmission channel is concrete and well-worn: war-risk insurance premia on Gulf transits reprice first, followed by freight rates and the prompt crude structure, with the front of the curve more sensitive than the back since the market treats the risk as a disruption to flows rather than to long-run supply. The distinction that matters is between rhetoric and action: verbal warnings alone have historically produced short-lived premia that fade within sessions, while an actual boarding or seizure sustains them. Worth noting is who is speaking, a security official via Nour News rather than the foreign ministry, which places this in the deterrence-messaging category rather than formal policy. The follow-ons are any US move against Iranian cargoes, IRGC naval activity near shipping lanes, and updates to war-risk cover terms from the London market.