Iran threatens Red Sea disruption if blockade continues; Chinese ship turns back

Iran’s military command threatened on Wednesday (April 15) to move to disrupt trade through the Red Sea if the U.S. naval blockade imposed on the country’s ports is not lifted.

To do so, Tehran could activate its Houthi allies, as it has warned before. The rebels, who control much of Yemen, previously caused major disruption to regional shipping routes during the 2023-2025 conflict between Israel and Hamas.

Armed with a large arsenal of missiles and drones, the Houthis have attacked Israel in support of Tehran during the current war. For now, however, they are observing the ceasefire announced by Donald Trump last Tuesday (April 7).

Any action in the Red Sea would affect not only Saudi oil exports through the port of Yanbu, but also inbound cargoes such as Brazilian agribusiness exports rerouted to the western coast of the Arabian Peninsula for access to Middle Eastern markets.

The blockade entered its third day on Wednesday, amid conflicting reports over how effective the measure has been. Trump ordered the move to pressure Tehran while negotiations continue over a possible peace deal between the rivals. The blockade adds to restrictions imposed by Iran itself: vessel traffic in the area, previously around 140 ships a day, has fallen to about 10% of that level.

The most notable case is that of the Chinese vessel Rich Starry, which is under U.S. sanctions for previously transporting Iranian oil and refined products. The ship had left the Persian Gulf and transited Hormuz between Monday (April 13), the first day of the blockade, and Tuesday (April 14).

On Wednesday, the vessel returned through Hormuz and is now anchored near Iran. It is carrying 250,000 barrels of methanol loaded in the United Arab Emirates, which in principle would place it outside the scope of the blockade.

It remains unclear whether the vessel paid the toll Tehran has sought to impose through a new route passing through Iranian waters in Hormuz, after saying it had mined the usual central shipping lane.

The previous day, Chinese President Xi Jinping used harsh language in condemning the conflict, while China’s foreign ministry described the restrictions as irresponsible and dangerous. In 2025, Iran was Beijing’s third-largest oil supplier.

In the opposite direction, Iran’s Fars news agency reported that a supertanker had broken through the U.S. blockade and reached an Iranian port to be loaded. There has been no confirmation of that transit from maritime traffic monitors, though vessels can avoid detection by switching off their identification systems.

According to maritime consultancies Kpler and LSEG, there is no record of any Iranian tankers leaving Hormuz since the embargo began. Even so, Tehran says there has been no damage because the United States has itself authorized trade in Iranian oil loaded outside the embargo zone, as a way to ease pressure on global crude prices.

According to Fars, Tehran is also considering using underutilized ports on the country’s southern coast, outside the embargo zone, although that appears difficult to implement. About 90% of Iran’s oil exports are shipped from the Kharg Island terminal in the Persian Gulf.

The United States says it has deployed 10,000 troops in the operation to track vessels running in “ghost mode,” with transponders switched off. U.S. military officials say at least two tankers were intercepted after leaving the Iranian port of Chabahar, but turned back.

The exact circumstances of those encounters remain unclear. Under the rules governing naval blockades, the enforcing navy first warns the vessel and, if unsuccessful, may board it with small boats or helicopters. The situation can then escalate to seizure or, in the event of resistance, the sinking of the ship.

According to regional vessel-tracking services, at least eight ships passed through Hormuz on Tuesday. They were heading to or leaving ports in other countries not covered by the embargo. U.S. officials told American media that the number may have reached 20.

Among the vessels that passed was another tanker under U.S. sanctions, the supertanker Alicia, which had been transporting Iranian oil since 2023. The ship was heading empty to load crude in Iraq, as was another vessel, Agios Fanourios 1.

The conflicting accounts come as the United States, which entered the war against Iran alongside Israel on Feb. 28 and froze hostilities last week, looks for a way out of the conflict before the current truce expires next Tuesday (April 21).

Trump gave several interviews on Tuesday night and, speaking to Britain’s Sky News, again said he hoped the conflict would end soon. In remarks to ABC, he said he expected developments within perhaps two days.

Direct negotiations with Iran, held over the weekend in Pakistan, are expected to resume. They did not produce an immediate solution, but the ceasefire has held, suggesting willingness on both sides to continue despite the blockade and Iranian threats.

On Wednesday, Iranian President Masoud Pezeshkian said his country prefers peace to war. According to Iran’s foreign ministry, a Pakistani delegation may arrive in Tehran on Wednesday to collect messages to be passed on to the Americans in preparation for the next meeting.

Trump, who has shifted his justifications for the conflict since the beginning, now appears prepared to settle for a solution to the Hormuz crisis and some form of agreement around Iran’s nuclear program.

Critics note that such an outcome could have been reached without war. In practice, the result may resemble the 2015 agreement, abandoned by Trump himself three years later, by seeking to freeze Tehran’s nuclear activities for a period.

Source: Folha de S. Paulo