US intelligence sees direct attacks by Iran on oil tankers as greater risk than mines

US intelligence reporting sees direct attacks by Iran as the greatest threat to oil tankers going through the strait of Hormuz, the key transit passage for the global oil trade that has been effectively shut down by the Islamic Revolutionary Guard since the start of the US-Israeli war against Iran.

The Trump administration, spooked by possible preparations by Iran to mine the strait, carried out strikes against 16 mine-laying vessels near the strait on Tuesday. US Central Command posted a video showing munitions hitting nine vessels, most of which were moored as they were struck.

But the more potent threat remains the risk of a direct attack by Iran at scale – for instance, a swarm of one-way attack drones or a series of shore-to-ship ballistic missiles, according to two people familiar with the intelligence who spoke on the condition of anonymity to discuss sensitive details.

The problem comes because just one missile or drone slipping through defenses could decimate or sink a tanker, giving Iran leverage even as the US launched what a senior administration official described as its largest attack against Iran in the conflict to date.

As a result, even if US navy destroyers escorted the tankers, they might not be able to intercept every incoming missile, and even in the event the Trump administration provides risk insurance directly to operators, ships’ crews would still need to be convinced to pilot the vessels through the strait.

Mines in some ways were more straightforward to deal with, because the US was prepared in advance of the war for the possibility of Iran attempting to mine the strategically important waterway through which a fifth of the global oil trade passes, the people said.

The issues with protecting oil tankers in the strait was discussed by US military officials in a classified briefing to top lawmakers on Tuesday, according to a person familiar with the matter.

Democrats emerged from the briefing deeply critical of the administration. “I can’t go into more detail about how Iran gums up the Strait, but suffice it say, right now, they don’t know how to get it safely back open,” the senator Chris Murphy wrote in a social media post after its conclusion.

A White House spokesperson referred questions about the risks in the strait to Donald Trump’s post on Truth Social on Tuesday, where he threatened military retaliation if Iran attempted to place mines. The US Central Command strikes on Iran’s mine-laying ships followed shortly after.

The strait of Hormuz is a key passage that connects the Persian Gulf to the northern Arabian Sea. The coastline of Iran runs along one side of the strait, and military and civilian vessels transiting through are at risk of shore-launched attacks as they enter or exit the gulf.

Since the start of the conflict on 28 February, the Islamic Revolutionary Guard has effectively shut down the strait and stranded oil tankers. The cut in supply has contributed to a steep increase in oil prices, which in turn have translated to higher gas prices for US consumers.

The energy secretary, Chris Wright, said in an interview with CNN’s State of the Union on Sunday that the US had successfully destroyed many of the weapons Iran might use to hit ships and expected regular traffic through the strait to resume in “a few weeks”, without providing details.

Still, fearing an attack by Iran, virtually all ship operators have stopped their tankers from passing through the strait. On Wednesday, at least three ships were hit in and around the strait, including one Japanese container vessel and two so-called bulk carriers that carry loose cargo like grain.

Only one of the bulk carriers, the Mayuree Naree from Thailand, appeared to be in the strait when it was attacked. The other vessels were in the Persian Gulf, according to marine tracking data. Iran claimed responsibility for the attack against the Mayuree Naree.