Houthi blockade threats and US-Iran conflict disrupt oil tanker traffic through Red Sea and Strait of Hormuz

Oil shipping disruptions at two of the world’s most critical maritime chokepoints intensified this week as the US-Iran conflict continued and Yemen’s Houthi militants threatened to fully blockade vessels calling at Saudi Arabian ports. In the Red Sea, tankers made unusual maneuvers — reversing course or coming to a near-stop — while traffic through the Strait of Hormuz fell to its lowest daily count since early May, with just three commodity vessels observed transiting on Tuesday and no observable traffic early Wednesday, according to Kpler tracking data.

Shipping traffic drops sharply at two key chokepoints

The numbers tell the story pretty clearly. Only three commodity vessels transited the Strait of Hormuz on Tuesday — the lowest daily count since early May, per Kpler tracking data. By early Wednesday, the waterway linking the Persian Gulf to global markets had gone quiet entirely, with no observable traffic detected.

The Red Sea looked similar. At least one vessel reversed course northward toward the Suez Canal, while others simply stopped mid-journey. Maritime-tracking data confirmed the unusual moves across multiple tankers — a signal that shipowners are recalculating risk in real time. When both chokepoints show disruption simultaneously, the ripple effects reach energy markets worldwide almost immediately.

For now, some vessels are still moving, some are waiting, and a few have already changed course entirely, leaving the full extent of the disruption still unfolding.

Houthi threats and US-Iran conflict drive the disruptions

Two overlapping pressures are pushing this latest wave of disruptions at once. Yemen’s Tehran-backed Houthi militant group has threatened to fully blockade all ships calling at Saudi Arabia’s ports — a direct escalation targeting one of the world’s largest oil exporters.

It’s not just talk. The Joint Maritime Information Center, a global naval security monitoring body, issued an alert late Tuesday warning that “the Houthis have completed preparations to attack shipping, including the deployment of missiles and drones.” The center cited sources it didn’t identify. Several shipowners also received direct email warnings from Houthi rebels telling them not to call at Saudi ports — messages that appear to have prompted immediate routing changes across multiple vessels.

The broader US-Iran conflict adds another layer. More than a week of tit-for-tat strikes has kept global energy markets on edge, and that combination is driving the sharp behavioral changes now visible in the shipping data.

Specific vessels alter or halt routes amid uncertainty

These disruptions aren’t abstract — they show up in the movements of individual ships. LPG tanker Gas King is one of the clearest examples. The very large gas carrier had been sailing south after picking up a cargo at the Saudi port of Yanbu, apparently bound for Japan, then reversed course and headed north out of the Red Sea via the Suez Canal instead.

That decision isn’t cheap. Asia-bound vessels rerouting through the Suez Canal face a longer voyage around the African continent plus additional transit fees — an unusual call that shows just how seriously shipowners are weighing the threat right now.

Supertanker New Explorer presents a different kind of concern. Carrying Saudi oil bound for Singapore, the 2025-built vessel appears to be idling in the Red Sea after loading at Yanbu, its status listed as “not under command,” though the reason for the near-stop isn’t clear. Aframax vessel Lahore also came to a halt after receiving a Saudi cargo, adding to the picture of widespread hesitation across the fleet.

Not everyone has stayed put. Tanker Xin Long Yang initially paused and reversed course after its owners received the Houthi email warning, but has since returned to its original southward route and is now heading toward Bab el-Mandeb. Some operators are still willing to proceed — though the calculus is clearly shifting by the hour.

Saudi oil exports and global energy markets under pressure

The timing of the Houthi threat makes it especially consequential. In the week ending July 17 — just before the threat emerged — Saudi Arabia had been exporting record volumes of crude from its Red Sea terminals, shipping 5.9 million barrels per day from the two terminals at Yanbu, according to tanker tracking data compiled by Bloomberg.

Those volumes flow through the Red Sea after traveling from Persian Gulf fields via Saudi Arabia’s East-West pipeline, making the Red Sea a critical link in Saudi export infrastructure rather than a backup option. Disruptions there cut directly into the kingdom’s ability to reach Asian buyers efficiently.

As of Wednesday, loadings at Yanbu appeared to be continuing, and some Asian buyers were still sending tankers into the Red Sea to collect their cargoes. The situation remains fluid, though, and the number of vessels willing to make that call could shrink fast if the security picture deteriorates. Brent crude futures have risen more than 25% this month as the conflict has escalated — a reflection of how seriously traders are pricing in supply risk.

What this means for global energy supply

Two of the world’s most important oil shipping corridors are showing simultaneous signs of stress. A Houthi blockade threat against Saudi ports and an ongoing US-Iran military conflict now more than a week old are driving it.

Saudi Arabia’s record export pace from Yanbu before the disruptions shows how much was flowing through the Red Sea route. Any sustained drop in tanker traffic there would have real consequences for Asian buyers who depend on those cargoes. The Strait of Hormuz, meanwhile, connects the broader Persian Gulf to global markets — and even brief stretches of near-zero traffic are an unusual and significant signal.

For now, some vessels are still moving, some are waiting, and a few have already changed course entirely, leaving the full extent of the disruption still unfolding.

Kelly Lippke

Kelly is an experienced writer with 15 years of experience exploring the big stories that shape our world, from tech breakthroughs and space exploration to climate, energy, and the fascinating quirks of science. She has a talent for turning complex ideas into sharp, memorable insights that stay with readers long after they’ve finished reading.