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Napoleon Bonaparte is said to have commented in connection with his invasion of Russia that “geography is destiny”. Take a look at a live maritime tracker to see how Napoleon’s aphorism is playing out in the Middle East today. There are presently hundreds of vessels either side of the Strait of Hormuz, idling in either the Persian Gulf or the Gulf of Oman. But nothing is passing though.

In normal times, 20% of the world’s oil flows through this waterway. But since the US and Israel began to launch attacks at the end of February, Iran has effectively closed down the Strait, both by depositing mines and by threatening to board any ships trying to pass without their permission.

The US has countered with its own blockade. And both sides have demonstrated how serious they are in recent days by threatening, boarding or forcing vessels to reroute.

That Iran would close the Strait of Hormuz should have come as no surprise to anyone. The leaders of the Islamic Republic have threatened to do so every time they have felt under threat over more than four decades. Christian Emery, an expert in US-Iran relations and Persian Gulf security at University College London, believes this is why no previous US president has chosen to launch a full-scale attack on Iran.

As we’ve already seen, the ability of Iran to hugely disrupt the global economy by shutting down the Strait was obvious: “The only person who seems not to have understood this is Donald Trump,” Emery concludes.

Read more: Has the Strait of Hormuz emerged as Iran’s most powerful form of deterrence?

So now there appears to be a deadlock. It’s an unwinnable........

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