Iran's Foreign Ministry warned all tankers transiting the strait of Hormuz 'must be very careful' while the situation remains insecure — the first time the war's Hormuz threat has been elevated from IRGC operational messaging to formal diplomatic communication.
The distinction in register carries legal and commercial weight. The IRGC had already struck two named tankers — the Marshall Islands-flagged Louise P and the Prima — publicly claiming both attacks and naming each vessel. But IRGC statements bind a military organisation. A Foreign Ministry warning binds the state. It places every flag state on notice that Iran's sovereign authority, not merely its armed forces, considers the strait contested. Under the UN Convention on the Law of the Sea, Hormuz is an international strait through which all vessels hold the right of transit passage. Iran's warning stops short of claiming the right to block transit. The IRGC's drone strikes demonstrate that compliance with Iranian terms is the practical condition for safe passage — the legal form and the operational reality have diverged.
The warning lands on a strait already partitioned by negotiation. Reuters reported Beijing in direct talks with Tehran for guaranteed passage of Chinese-linked crude and Qatari LNG. Fortune reported Chinese-flagged and 'Muslim'-owned vessels receiving de facto IRGC protection from interdiction. China's 48th PLA Navy fleet deployed to The Gulf the same day. The FM statement codifies what was already operational: a two-tier waterway, open for approved commerce, hazardous for the rest. During the 1987–88 Tanker War, Iran and Iraq between them attacked 546 commercial vessels in The Gulf over eight years. The current conflict has produced a more discriminating system — not indiscriminate attacks on shipping, but selective enforcement that rewards alignment with Tehran and Beijing.
For the tanker and insurance markets, the FM escalation compounds an existing paralysis. Every major P&I club cancelled War risk coverage effective 5 March. Tanker traffic is down approximately 70%. Kuwait declared force majeure on all exports. VLCC freight rates hit an all-time high of $423,736 per day. A formal government warning adds a new dimension: flag states whose vessels are struck can now point to an explicit Iranian state-level caution as evidence of premeditated threat, strengthening both insurance claims and potential proceedings under international maritime law. The FM's choice of words — 'must be very careful' rather than 'will be stopped' — preserves deniability while achieving the same deterrent effect.
