Roughly a fifth of the world's oil moves through the Strait of Hormuz every single day. Right now, the law that guarantees ships can pass through it freely is being tested by a state that never fully signed up to it.

THE LAW SAYS PASSAGE IS FREE. THE INSURERS SAY OTHERWISE.

Here's what each side is actually calculating. Iran cannot legally close Hormuz - UNCLOS Article 44 bars suspending transit passage and even Iran's own signed-but-unratified position doesn't claim otherwise. So Iran isn't trying to close the strait; it's trying to make the cost of using it Iran's to set, through the Persian Gulf Strait Authority's permits and mandatory insurance requirements.

That's a deliberate distinction: violating the letter of UNCLOS invites international censure Iran can't currently absorb; asserting administrative control over passage - permits, approved insurers - creates de facto leverage without technically closing anything.

Where International Law Actually Runs Out

UNCLOS guarantees the legal right to transit. It says nothing about who insures the ship making that transit and that gap is exactly where this crisis lives. A tanker has the legal right to pass through Hormuz. It does not have the practical ability to pass if no insurer will underwrite the voyage - and after Iranian strikes on vessels including the Qatari LNG carrier Al Rekayyat, insurers are doing exactly what the law cannot force them to do: pricing in the risk regardless of what UNCLOS says.

Weekly transits nearly halving between two consecutive weeks in early July is not a legal outcome - it's a market one and it's the real mechanism by which "law says X" and "reality does Y" diverge.

What the Malacca Contrast Actually Proves Critics of

Iran's approach point to the Straits of Malacca and Singapore, where Indonesia, Malaysia and Singapore run a voluntary Aids to Navigation Fund rather than mandatory tolls - proof, the argument goes, that cooperative UNCLOS-compliant management works even in a heavily trafficked chokepoint.

That comparison is accurate but incomplete: Malacca's littoral states aren't in active armed conflict with the parties transiting it. The contrast that matters for the exam isn't "cooperative model versus coercive model"

• it's that international maritime law was built to manage peacetime chokepoint traffic and has no real enforcement mechanism once a chokepoint becomes contested territory in an active war. That is precisely the gap Iran's PGSA is exploiting and precisely why India's shipping insurance costs are rising regardless of what UNCLOS technically guarantees.