Ninety per cent of world trade moves by sea — and the Iran–US conflict sits astride two of its most vital arteries: the Strait of Hormuz and the Red Sea. When the conflict heats up, the world's shipping map redraws itself within days.
The Two Chokepoints
- Hormuz carries the oil and gas (full explainer) — no meaningful detour exists.
- The Red Sea / Bab el-Mandeb carries the containers — the Asia–Europe trade via Suez. Iran's Houthi partners demonstrated after 2023 that this artery can be effectively closed to Western-linked shipping: hundreds of attacks drove most container lines to reroute around the Cape of Good Hope, adding roughly 10–14 days and major fuel costs per voyage, collapsing Suez Canal transits and Egypt's canal revenue.
The Insurance Trigger
The fastest-acting weapon in maritime conflict is not a missile — it is the war-risk insurance premium. When underwriters reclassify the Gulf or Red Sea, premiums can multiply within hours, adding hundreds of thousands of dollars to a single tanker voyage; at the extreme, insurers simply withdraw cover, which halts traffic as surely as a blockade. During the June 2025 war, war-risk rates for Hormuz transits spiked, some owners paused fixtures, and charter rates for tankers jumped — costs that flow into every barrel and container.
Grey Zone Tactics
The conflict's signature maritime tools stop short of open warfare:
- Tanker seizures: Iran has repeatedly detained foreign tankers (often framed as legal disputes) as retaliation for sanctions enforcement, including tit-for-tat seizures with the UK in 2019
- Sabotage: limpet-mine attacks on tankers near Fujairah and in the Gulf of Oman in 2019, attributed to Iran
- GPS interference: widespread jamming and spoofing around the Gulf during the 2025 war degraded navigation for hundreds of vessels
- The shadow fleet: hundreds of ageing, obscurely-owned tankers moving sanctioned Iranian (and Russian) oil outside Western insurance — a parallel shipping system born of sanctions
What June 2025 Proved
Despite the heaviest fighting in the conflict's history, Hormuz never closed — tankers kept transiting throughout, at higher cost and with longer queues. The system bent, priced the risk, and carried on: testament both to the market's adaptability and to the fact that even at war, neither side wanted the strait shut.
The Permanent Residue
Each crisis leaves the system costlier: rerouting habits, elevated insurance floors, security escorts, longer contracts hedging against disruption. These embed as a quiet, permanent tax on global trade — one of the ways the Iran–US conflict feeds world inflation even in years when no missile flies.
This article is part of a 20-part analysis series on the Iran–USA conflict covering the complete history, the June 2025 war, the Strait of Hormuz, oil markets, global inflation and future scenarios. Facts reflect the situation as of early 2026.
