Hormuz Is Functionally Constrained as Security Risk Outruns US Escort Effort
Visible traffic has collapsed, but dark transits, disputed attacks and parallel routes make the scale of the disruption harder to measure.
The central judgement is that the Strait of Hormuz is functionally constrained, not proven fully closed. Visible transits fell to four on 15 September, against a 10-day average of 18, after counts fell from 12 to seven on 9 September. Yet AIS-off passages and US-reported facilitated movements make the true flow uncertain. On 15 September, no very large crude carrier or LNG tanker was recorded.
Security risk is driving a commercial pause. JMIC rates the threat severe, with deliberate hostile action highly likely; UKMTO also reports projectile strikes and continuing mine warnings. The US is offering timed passage on a southern route, while Iran has threatened penalties against 77 ships and links reopening to US commitments. A temporary Iran-Oman arrangement may improve access, but no reopening has been confirmed. The near-term pattern is likely to be selective, escorted traffic, elevated freight and energy prices, and continued risk to crews.
- Hormuz's visible traffic fell to four transits on 15 September, roughly 78% below the 10-day average of 18.
- AIS and official US counts diverge sharply: about six southern-route passages daily were visible, against about 20 US-facilitated.
- No VLCC or LNG tanker crossed on 15 September, signalling selective rather than normal commercial access.
- JMIC rates the threat severe; mines, projectiles and alleged Iranian attacks keep crews and owners risk-averse.
- Iran's 77-ship warning gives Tehran a legal and operational lever over future passages.
- An Iran-Oman route is under discussion, but reopening depends on US-Iran commitments and remains unconfirmed.