PARIS – Washington’s decision to blockade Iranian ports in the Strait of Hormuz is sending tremors through global energy markets, raising fears of a fresh oil shock by threatening supplies to Asia. Iran had continued to pump crude to Asia since the start of the Middle East war, partly shielded by its elusive “dark fleet”.
Roughly one-fifth of the world’s oil normally flows through the vital waterway. In recent weeks, Iran has already tightened the screws, sharply slowing maritime traffic and reportedly charging transit fees.
Now the additional blockade of Iranian ports ordered Sunday by US president Donald Trump threatens to land another blow to global oil and gas supplies after the fighting damaged energy facilities in the Gulf states and blocked their exports through the Strait, said Amir Handjani of the US-based Quincy Institute for Responsible Statecraft.
Just days after launching the war against Iran with Israel on 28 February, the US temporarily eased some sanctions on Tehran to prevent an abrupt energy shock, particularly for Asian economies.
On Sunday, the Felicity, a tanker operated by the National Iranian Tanker Company (NITC), delivered two million barrels of oil to India, the first such above-board shipment since 2019, according to tracking site Tanker Tracker.
Oil still flowing
Iranian crude had been helping ease market pressure to meet demand so far, Handjani told AFP, warning that the blockade now threatens that fragile balance. “What is the US Navy going to do? They’re not going to confront Chinese, Indian and Pakistani merchant ships” loading in Iranian ports, he said.
“That’s an act of war.”
China remains the world’s largest importer of Iranian crude, and on Tuesday said the US blockade was “dangerous and irresponsible.”
Oil prices, already climbing, will continue to surge, Handjani predicted. Prices jumped 8% to above US$100 a barrel in early Asian trading Monday, just hours after the blockade was announced. For expert Elisabeth Braw of the Atlantic Council, “it’s a bit of a Hail Mary move” by Washington after it had “exhausted all options”
Blockading merchant ships violates the UN Convention on the Law of the Sea and is illegal, she noted. According to data from commodities tracking firm Kpler analysed by AFP, Iran has exported an average of about 1.8 million barrels of crude per day by sea since early March. That is slightly above its 2025 average of around 1.7 million per day. Between 1 March and 12 April, 58 oil tankers transited through the strait carrying cargo, according to AFP analysis of Kpler data. Nearly 80% set off from Iranian ports, mainly Kharg Island, or flew the Iranian flag, hauling a total of 11 million tonnes of crude.
Many of those vessels belong to Iran’s “dark fleet”, made up of ageing ships operating for years in deep opacity, with unclear ownership, false flags, lack of insurance or manipulated GPS data, all with the intent to dodge international sanctions, experts told AFP. – Nampa/AFP