I knwo it's not really directly Ukraine-related but this UNITED24 article about Iran charging for the use of the Straits of Hormuz seemed helpful
Iran has told brokers it will limit the number of ships passing through the Strait of Hormuz to about a dozen a day and will charge fees under a ceasefire brokered during the presidency of Donald Trump.
“Ships that do pass will have to coordinate with the Islamic Revolutionary Guard Corps,” Arab brokers said.
Only four ships were allowed to pass on Wednesday, the fewest since early April, according to S&P Global Market Intelligence, down from more than 100 a day before the war.
Iran requires ships to agree on payment terms in advance and to make payments in cryptocurrency or Chinese yuan, brokers said.
Iran’s demands suggest it has used the war to create new leverage and, potentially, a source of revenue.
During the fighting, Tehran effectively took control of the strait, attacking ships that tried to pass without its permission.
The arrangement is being enshrined in a two-week ceasefire that the United States and Iran agreed to on Tuesday.
The United States has publicly insisted on free and open passage through the strait. But Iran has shown no sign of loosening its grip.
On Wednesday morning, Iranian forces in the strait broadcast a VHF maritime warning that vessels without permission from the Islamic Revolutionary Guard Corps Navy risked being destroyed, according to a recording provided to The Wall Street Journal by a crew member.
Iranian Foreign Minister Abbas Araghchi said that traffic through the strait during the two-week truce would be under the control of Iranian armed forces. His comments, posted on social media, were widely shared by Trump and the White House.
The Trump administration’s acceptance of these terms could cement Iran’s dominance over a large portion of the world’s oil supply — about 20 million barrels per day, or roughly 20 percent.
Just six weeks ago, ships were allowed to pass through the strait without any military coordination with Iran.
The new terms change the balance of power in the Persian Gulf and expand Iran’s global influence, despite the losses it has suffered in the five-week war.
Shipping companies say Iran is already shaping a system of fees. In recent weeks, it has been working to introduce a tiered approach: ships carrying Iranian oil or goods pass freely; ships from friendly countries pay a fee; ships from countries that support the United States or Israel are not allowed at all.
Market operators say the fees are set about a week in advance and depend on the size of the vessel: for a supertanker capable of carrying about 2 million barrels of oil, the fee can reach $2 million.
“Iran’s parliament has approved a new plan for managing the strait, which includes fees and the need to obtain an Iranian permit for transit,” the state news agency IRNA reported.
Representatives of the Gulf Arab states emphasize that Iran’s initiative violates international treaties, in particular the UN Convention on the Law of the Sea, which guarantees freedom of navigation.
Institutionalizing such fees will be difficult. Unlike Egypt or Panama, which charge fees for passage through canals, international maritime law does not allow states to charge for transit through natural straits such as the Strait of Hormuz, the English Channel, Gibraltar, or Malacca.
“This is the kind of economic disaster that everyone could have predicted and everyone predicted, but Trump did it anyway,” said Erik Meyersson, chief emerging markets strategist at Swedish bank SEB.
“We have a paradox: complete dominance of the air and, at the same time, a complete inability to control the Strait of Hormuz,” he added, commenting on the US presence in the region.
Blocking the strait is already leading to rising global food prices and broader inflation.
It is also a key route for transporting fertilizers and chemicals such as helium, which is used in semiconductor manufacturing.