AP — A focal point of the Iran war is increasingly about who controls the Strait of Hormuz — a narrow, elbow-shaped waterway that for decades was a relatively safe and reliable transit route for Middle East oil and natural gas supplies.

By saying that an interim ceasefire gave it the right to establish the terms under which ships traversed the strait, and threatening and firing upon vessels that did not use its preferred route, Iran has sought to exert control over the waterway and gain negotiating leverage with the United States.

On Monday, US President Donald Trump sought to tip the scales. He reimposed a blockade on Iran and said the United States controls the strait and would charge fees to ships for safe passage — essentially borrowing from the Iranian playbook.

The announcement came as the US and Iran have been ramping up attacks against each other to assert control over the strait, threatening a return to all-out war.

The world has long considered the strait — which passes the coastlines of Iran and Oman — a free-to-use, international waterway. But soon after it was attacked by the US and Israel on February 28, Iran claimed sovereignty over it, disrupting world energy markets and driving up prices.

Here’s a closer look at the facts.

Both Iran and the US say they control the Strait of Hormuz

In a posting on Truth Social on Monday, Trump said the US “will be, from this point forward, known as THE GUARDIAN OF THE HORMUZ STRAIT.”

Iran’s paramilitary Revolutionary Guard, which controls the Islamic Republic’s ballistic missile arsenal, says Tehran controls the strait. “We will not allow a rogue and child-killing army from the other side of the world to continue its illegal interference in it,” the Islamic Revolutionary Guard Corps said Sunday.

According to the United Nations Convention on the Law of the Sea, established in 1982, no country has the right to claim international waters and all ships have the right of unimpeded passage.

Even though the US and Iran haven’t ratified the convention, “that doesn’t matter, because this has become part of universal custom, so all states can rely on it under all circumstances,” said Marc Weller, director of the International Law Program at the University of Cambridge.

Still, both Iran and the........

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