On Monday, Iranian Foreign Minister Abbas Araghchi pushed back against President Donald Trump's plan to impose a 20% fee on cargo moving through the Strait of Hormuz — but not in the way you might expect. He actually agreed with the premise.

Araghchi took to X to respond to Trump's announcement that the U.S. would become the "Guardian of the Hormuz Strait" and charge a 20% fee on all cargo passing through one of the world's busiest oil shipping routes. His response was a masterclass in diplomatic trolling.

"POTUS is absolutely right. Whoever provides secure and safe passage of commercial vessels through the Strait of Hormuz should be compensated for this service," Araghchi wrote.

Then came the twist: "Iran has always been the GUARDIAN of the Strait and will remain so FOREVER," he added, before concluding, "20% is of course too much. We will be fair."

So the two sides agree on the concept — someone should get paid for keeping the strait safe — but disagree on who that someone is and what the fee should be. It's like arguing over who gets to run the toll booth and how much to charge, except the toll booth happens to be a strategic waterway that carries roughly one-fifth of global oil shipments.

Trump, meanwhile, announced the fee on Truth Social, saying the "process and formation will begin immediately." He also said the U.S. would reinstate its blockade of Iranian ports near the Strait of Hormuz, with U.S. Central Command saying the move would resume Tuesday at 4 p.m. ET.

Trump wrote that the strait "is OPEN, and will remain OPEN, with or without Iran," while asserting that countries other than Iran would continue to enjoy "fair and open use" of the passage.

The Strait of Hormuz is one of the world's most strategically important maritime chokepoints, handling about 20% of global oil shipments. Any disruption there can send energy markets into a tailspin.

International Law Questions Trump's Proposal

Trump's proposed cargo fee quickly drew criticism from international maritime authorities. In a statement to CNBC, the International Maritime Organization said there is "no legal basis" for imposing mandatory transit tolls on ships using an international strait.

That position aligns with earlier comments from Secretary of State Marco Rubio, who said that "no country is allowed to charge tolls or fees on an international waterway" under existing international law. So the U.S. position appears to be: we can charge fees, but no one else can.

The latest exchange comes as military tensions between Washington and Tehran continue to intensify. With both sides claiming guardianship of the strait and neither backing down, the situation remains volatile — and the world's oil markets are watching closely.