Guest Post by Nick Giambruno

At this point, the whole Iran war comes down to one thing: who controls the Strait of Hormuz.

The Strait of Hormuz is a narrow strip of water that links the Persian Gulf to the rest of the world.

It’s the world’s single-most important energy corridor, and there’s no alternative route.

Before the current war broke out, roughly 20 million barrels of oil per day passed through the Strait, according to the US Energy Information Administration. That is about 20% of global oil production. Another 20% of global LNG exports also moved through it each day.

It is difficult to overstate how important Hormuz is to the global economy. If it were disrupted for a prolonged period, it could cause an energy crisis and a global economic depression.

And that is exactly why Hormuz matters so much in this war.

Thanks to its commanding geography, missile reach, naval mines, drones, and decades of preparation for unconventional warfare, Iran can shut the Strait down—or at least make it too dangerous for normal commerce to continue.

That’s why the US Navy doesn’t even dare to venture too close and hasn’t been anywhere near the Persian Gulf since the war started.

There’s not much anyone can do about Iran’s control over the Strait short of a large-scale ground invasion and occupation of the country, which would itself be an extremely risky and uncertain undertaking.

Hormuz is Iran’s geopolitical trump card, and it is now being played.

If you wanted to distill it down to a simple scoreboard of who is winning and who is losing the war, there is probably nothing better than the chart below, which shows oil tanker arrivals through the Strait of Hormuz.

Until the Strait of Hormuz is fully reopened to the US and its allies at prewar levels, Washington cannot credibly claim it is winning the war.

Before the war, an average of about 53 oil tankers entered the Strait each day. Now, there are perhaps a couple at best.