The US has reimposed a naval blockade on Iranian ports, leading to immediate responses from Iran-linked oil tankers in the Strait of Hormuz. US Central Command (Centcom) reported firing Hellfire missiles into the smokestack of the tanker Belma after it ignored multiple warnings while heading towards Iran's Kharg Island oil terminal. This incident occurred shortly after President Donald Trump reinstated the blockade, citing alleged Iranian attacks on commercial vessels. Another crude oil tanker, Fuyao, under US sanctions, reversed course and returned to Iranian waters after initially heading for Pakistan with a cargo of oil. These actions follow a period of eased sanctions where Iran exported at least 74 million barrels of oil, valued at over $6 billion, between April 13 and June 18.
Iran's "dark fleet" has continued to employ evasion tactics to circumvent the blockade and sanctions. Maritime risk intelligence company Windward identified 23 Iranian-linked vessels in or near the Strait of Hormuz that disabled or manipulated their Automatic Identification System (AIS) transponders or used deceptive identity practices. Cargo intelligence firm Vortexa noted that 10 of these vessels were carrying cargo, while 13 were empty. These sophisticated methods allow Iran to continue substantial oil exports, with Windward estimating about 50 million barrels of crude exported in June alone, peaking at around 10 million barrels in a single day.
Despite the blockade, Iran relies heavily on these clandestine shipping networks, shadow companies, and opaque financial arrangements, as oil exports account for about half of its government revenue. The renewed US blockade poses significant challenges, increasing shipping risks, insurance costs, and transaction complexity, which forces Iran to rely more heavily on deceptive practices to maintain oil flow, particularly to buyers in Asia, with China purchasing approximately 80% of Iran's crude exports. The effectiveness of the blockade will depend on how well Iran's shadow fleet can offset intensified US enforcement.
The reimposition of the blockade and the resulting tensions have had an immediate impact on global oil markets. Brent crude oil, while seeing a slight dip on Thursday, was still up 11% for the week, trading around $84.50 a barrel due to the renewed hostilities. Shipping traffic through the crucial Strait of Hormuz has also plummeted, with only 11 fuel tankers and cargo vessels crossing on Wednesday, a significant drop from the pre-conflict average of 138 per day, according to Kpler data. RBC analysts suggested that traffic would not return to pre-war levels as long as threats such as mines, missiles, and drones persist, further highlighting the escalating conflict's impact on oil supply routes.
