Hormuz Tanker Traffic Slows Again as US, Iran Trade Strikes
The fragile June truce is fraying. Here's what the flow data shows.
Photo by Joshua Woroniecki on Unsplash
Tanker crossings through Hormuz dropped to 13 per day this week, down from 33, after Iran attacked three ships and the US retaliated with airstrikes.
The Numbers Tell the Story
Daily tanker traffic through the Strait of Hormuz fell sharply this week. According to Kpler data, only 13 tankers crossed on Wednesday compared with an average of 33 per day over the previous week. That's a 60% drop in a single session. Windward reported just five commercial ships crossed overnight into Thursday.
The southern corridor, a route hugging the Omani coast and coordinated by US naval forces, saw virtually no traffic. Lloyd's List Intelligence reported that no vessels above 10,000 deadweight tonnage have transited that lane with transponders on since July 7. Some ships are believed to have crossed "dark," switching off their automatic identification systems to avoid tracking.
The pattern here matters. Ships are either routing through Iranian controlled lanes or going invisible. Neither scenario suggests confidence in the truce framework that was supposed to reopen the strait.
What Triggered the Breakdown
The escalation began earlier this week when Iranian forces attacked three commercial tankers transiting Hormuz. The US responded with two rounds of airstrikes targeting military infrastructure on Iran's southern coast and eastern provinces. President Trump declared the ceasefire "over" on Wednesday.
Iran retaliated Thursday with strikes against US military sites in Bahrain, Kuwait, Qatar, Jordan, and Iraq. Tehran has not claimed responsibility for the tanker attacks, but analysts note this fits a pattern. Iran uses sporadic attacks to gain leverage in negotiations while maintaining plausible deniability.
The June 17 memorandum of understanding was supposed to guarantee safe passage. Under that interim deal, the US ended its naval blockade of Iranian ports and Iran agreed to ensure commercial ships could transit. Tehran demanded vessels use a northern route under its control, while the US supports a southern corridor along Oman. That dispute never got resolved, and now it's blowing up.
The Oil Market Response
Crude prices are on track for weekly gains of 4% to 5% after the flare up. Oil has rallied more than 6% since the hostilities resumed. But the market isn't pricing in a complete closure. Andy Lipow of Lipow Oil Associates noted Thursday that oil prices reflect disruption risk, not a total shutdown scenario.
The IEA reported that global oil supply rose by 4.1 million barrels per day in June as strait traffic resumed. That recovery looks fragile now. Supply remains 9.4 million bpd below pre war levels, and the progress made since June is at risk of reversing.
Windward analysts put it bluntly: Hormuz is operating again under full conflict conditions. The collapse of the ceasefire framework, reimposition of Iranian oil sanctions, and the scale of US kinetic action represent the most significant escalation since the conflict's opening phase in February.
The Competing Claims Over Control
Tehran and Washington are fighting over something more fundamental than transit fees. They're fighting over who controls the waterway itself. Iran has effectively claimed sovereignty over Hormuz since the war began in late February, when the US and Israel launched airstrikes and Iran responded by threatening all commercial shipping.
Iran's military has warned that all vessels must use routes designated by Tehran for safe passage. Any deviation will be "met with the immediate and powerful response of the Armed Forces." The US position is that Iran does not control the waterway and that America's strikes aim to keep the strait open.
Before the war, Hormuz handled about 25% of the world's seaborne oil trade and 20% of global LNG. When fighting began, tanker traffic dropped to almost nothing. The June deal brought some recovery. This week's events show how quickly that recovery can unwind.
What Shipowners Are Doing
The response from shipping companies has been mixed but cautious. Of five shipowners surveyed by Bloomberg whose vessels had crossed Hormuz in recent weeks, three said they were assessing whether it's still safe to transit. Two said they hadn't changed their policies yet.
Insurance premiums for strait transit had already climbed before the February attacks, rising from 0.125% to between 0.2% and 0.4% of ship insurance value. For very large oil tankers, that's an increase of a quarter million dollars per crossing. Those costs are likely climbing again.
The core problem is that ships can't be in two places at once. Use the northern Iranian corridor and you're signaling compliance with Tehran's sovereignty claims. Use the southern Omani route and you're a potential target. Go dark and you lose your insurance coverage. None of the options are good.
What to Watch
The next 48 to 72 hours matter. If daily transit counts stay in the single digits or low teens, insurance markets will price in higher risk and shipping companies will pull back further. That creates a self reinforcing loop where reduced traffic justifies reduced traffic.
Watch Iranian statements about the northern corridor. If Tehran offers explicit safe passage guarantees for vessels using its route, some shipowners will take that deal regardless of the geopolitical optics. The practical question for shipping companies isn't who controls the strait legally. It's whether their cargo gets through.
Oil traders should monitor the spread between Brent and Dubai crude. A widening spread would signal that Middle East supply is getting harder to move while Atlantic basin oil remains accessible. That divergence would confirm the market is taking the disruption seriously.
For informational purposes only. Not investment advice. Published Friday, July 10, 2026.