Geography
The Strait of Hormuz connects the Persian Gulf to the Gulf of Oman and onward to global shipping lanes. The strait is approximately 39 km wide at its narrowest point between the Musandam Peninsula (Oman) and Iranian territory. The traffic separation scheme — inbound and outbound shipping lanes plus a central buffer — runs almost entirely through Omani territorial waters.
What flows through it
- Roughly 20% of global oil consumption (figures shift; the order of magnitude does not).
- A substantial share of global LNG, particularly Qatari production.
- Inbound consumer goods, machinery, and food for the Gulf economies.
Threat history
Iranian threats to close the strait recur with each major round of US-Iran tension. Actual closure has not occurred in modern history. The 1980s "tanker war" (during the Iran-Iraq war) produced sustained disruption short of closure. Multiple US-Iran near-incidents have occurred — vessel boardings, drone shootdowns, tanker seizures — none escalating to durable closure.
Why threatening closure is easier than achieving it
- Closure requires sustained suppression of traffic across a 39 km strait; harassment is far easier.
- Iran's own oil exports also flow through Hormuz; closure imposes symmetrical costs.
- US and allied naval presence (Fifth Fleet, Combined Maritime Forces, RN, French Navy) is positioned specifically for this scenario.
- Iran's actual leverage is the threat itself: insurance markets and freight rates respond to plausibility, not just to events.