Iran declares Hormuz closed, a supertanker with over two million barrels of oil in flames: who draws the "permitted" routes?

Iran's Revolutionary Guard has once again sent the message shipping companies already know by heart: the Strait of Hormuz is closed and foreign ships have no right of passage. Anyone who breaks Iran's rules, Tehran warns, puts the safety of their own voyage on the line. Translated from diplomatic language: you sail at your own risk.

The message came after yet another fire at sea. A supertanker carrying more than two million barrels of crude oil struck a naval mine while, according to the Guard, trying to pass along an "unauthorised route". Iran's version goes further: the crew allegedly switched off navigation and radar systems and sailed "with the support of smugglers and American terrorist forces". The tanker's name, the flag it sails under and the company that owns it are so far unknown. There's no official information on the crew or any casualties either. And one more thing that mustn't get lost in the noise: Iran's claims about the cause of the explosion have not been independently verified.

This isn't an isolated incident, it's a series. On both 10 and 12 October the Guard announced an almost identical scenario: tanker, unapproved route, systems switched off, mine. The British maritime security service UKMTO recorded several attacks, but in some cases it speaks of unknown projectiles, without confirming Iran's story about mines. According to the Financial Times, 24 ships were attacked in the region in the two weeks to 11 October alone. And since yesterday, as Al Jazeera reported, at least two more tankers have been hit off the coast of Saudi Arabia. When Tehran says mine and British services write "unknown projectile" - who is the captain who has to get through supposed to believe?

The waters around the strait are slowly becoming a graveyard for merchant ships. On 14 October the container ship GFS Pride sank; it sailed under the flag of Singapore and, according to reports, carried almost 2,500 containers of luxury goods destined for the Dubai market. Perfumes and phones floated on the sea, according to footage that emerged after the sinking.

Shipping through Hormuz has been seriously disrupted since 28 February, when US and Israeli strikes on Iran began. Tehran responded by restricting passage and attacking ships it says break its rules. The consequences are measured in dollars: shipping and tanker insurance have become drastically more expensive, and Brent crude on 16 October reached almost 110 dollars a barrel.

Through this narrow passage flows a fifth of the world's oil and around 20 percent of liquefied natural gas, most of it from Qatar. That's why every new "unauthorised route" is a message to the whole world, not just to the captain of one tanker. The Balkans know well what it looks like when someone draws the lines of what's permitted on their own and calls it order. The question is how many more tankers have to burn before someone sits down at a table instead of in front of a radar.