Saudi Arabia said on Wednesday that an Iranian attack had struck an oil tanker owned by its national shipping company. Two Filipino seafarers were killed.

Iran added eleven more vessels to its blacklist the same day.

Those two sentences describe the two ends of the same system, and almost every account of the Hormuz crisis reports only the second.

Who is actually on these ships

The Philippines supplies roughly a quarter of the world’s merchant seafarers — the largest single national contingent in global shipping. Filipino crews are aboard tankers, bulk carriers and container ships flying flags with no connection to the Philippines, owned by companies headquartered somewhere else again, carrying cargo for a third party.

That layering is ordinary in shipping and it has a consequence in wartime. When a vessel is attacked because of what it is carrying or whose flag it flies, the people killed generally have no connection to the dispute at all. They are employees on a fixed-term contract, sending money home.

The two men killed this week join a pattern running through this conflict. A missile attack on a vessel earlier in the escalation also killed several crew. Seafarer deaths are recorded in maritime bulletins and insurance notices, and rarely in the coverage of the war that produced them.

What a blacklist does

Iran’s list of designated vessels is a targeting instrument dressed as an administrative measure. Ships on it are declared legitimate objects of interdiction on the stated grounds of their ownership, cargo or destination.

Its practical effect is felt first in insurance. War-risk premiums for the Gulf are recalculated against exactly this kind of announcement, and a listed vessel becomes more expensive to cover or uninsurable on that route. Owners then reroute, which adds days and fuel, or they accept the premium and pass it on. Either way the cost reaches the cargo.

This is the mechanism we set out in our earlier explainer on how shipping registries and ownership structures obscure who is responsible for a vessel. The same opacity that lets sanctioned cargo move also makes it harder for anyone to establish who a crew works for when something happens to them.

Saudi Arabia’s position is now awkward

A ship owned by the Saudi national shipping company being struck by Iran is a different order of event from a strike on a foreign-flagged vessel of unclear ownership.

Riyadh is simultaneously managing the Houthi naval blockade in the Red Sea, which has already drawn it into an escalation with Yemen, and trying to avoid being drawn directly into the war between the United States and Iran. An attack on state-owned property narrows that room.

What Saudi Arabia has not done is characterise the strike as an act of war requiring a military response. That restraint is the thing to watch, and it is a choice rather than an inevitability.

The protection that does not exist

Merchant seafarers are civilians. A merchant ship carrying ordinary commercial cargo is not a military objective, and attacking one is unlawful under the law of naval warfare unless the vessel is making an effective contribution to military action.

The difficulty is enforcement. There is no mechanism by which the family of a Filipino deck officer killed in the Gulf obtains a finding about who fired, or compensation from anyone other than an insurer. Manila can make representations. Flag states can protest. Neither produces a ruling.

Seafarers’ unions and the International Maritime Organization have pressed for years for stronger guarantees in conflict zones, with limited effect, because the states that would have to provide them are frequently the states doing the attacking.

What to watch

Two things. Whether Manila makes a formal démarche over the deaths, which would be the first test of whether a labour-supplying state has any leverage in this. And whether war-risk premiums move sharply enough on the new designations to close routes, since insurance, not naval escort, is what actually determines which ships sail.

Sources

• Reuters reporting on the attack on the Saudi-owned tanker, 2 September 2026
• Just Security Early Edition, 3 September 2026
• International Chamber of Shipping seafarer workforce data
• San Remo Manual on International Law Applicable to Armed Conflicts at Sea