What Centcom actually counted

Centcom's statement on Tuesday carried two things at once. The first was an incident: an MH-60 helicopter fired two Hellfire missiles into the engine room of the Panama-flagged M/V Vela Nova in the Gulf of Oman after, it said, the crew ignored repeated warnings, and the ship was no longer heading to Iran. The second was a running total. As of 11 August, Centcom said it had redirected 55 commercial vessels attempting to run the blockade, disabled 3 non-compliant vessels and boarded 2.[1]

This column argued on Monday that US officials were describing a squeeze on Iran while the only public evidence they offered was the oil price. Centcom's counts are the first published series that measures the blockade's own operations. They remain Centcom's own tally, unchecked from outside, and Iran has not commented. They still name discrete, repeatable actions with a date attached, which a price cannot do.[1], [3]

Two series, two different constraints

A second series runs alongside it. Al Jazeera, citing MarineTraffic, reported 15 crossings of the Strait of Hormuz on Friday, 11 on Saturday and 6 on Sunday, with 17 vessels using routes Iran had designated and 10 using routes the tracker could not determine. That is traffic through the waterway, measured by a commercial tracking service.[2]

The two series do not measure the same thing. Centcom's counts cover ships heading for Iranian ports, which its blockade is built to cover. The crossing counts cover everyone using the strait, which Iran itself closed and which shipowners avoid for reasons that include war-risk insurance and the expense of a longer voyage. A blockade on one country's ports and the closure of a waterway many countries use can move the same way without either one driving the other.[2], [1]

What would separate them?

Separating them needs the two series to move apart. If Centcom's redirected count keeps climbing while crossings stay in single digits, enforcement is doing work on Iran-bound traffic that the closure alone does not explain. If that count flattens while crossings recover, the binding constraint was the closed strait, and the blockade was working on a shrinking pool of ships. A cumulative figure is what Centcom publishes, so the useful quantity is the weekly increment rather than the total it is added to.[1], [2]

The Vela Nova sets the price at the enforcement point. Two missiles into an engine room, with nothing said about whether the crew was hurt, is the cost a shipowner now weighs against whatever an Iranian port pays. The gap between 55 redirected and 3 disabled suggests most masters turn before that cost is charged, and the redirected figure, more than the disabled one, is what will show whether the blockade is holding.[1]