US walks back assessment that 'Mercer Street' drone attack was launched from Yemen

The US Defence Department on Tuesday walked back a senior official's testimony before the Senate, which initially appeared to confirm that last month’s attack on the Israeli-operated oil tanker Mercer Street had been launched from Yemen.

Dana Stroul, deputy Assistant Secretary of Defence for the Middle East, initially confirmed reports the attack had been launched from Yemen while testifying on US arms sales to the Middle East before the Senate Foreign Relations Committee.

"Yes, I can confirm those reports," she told Republican Todd Young before proceeding to corroborate an earlier assessment that the attack had been carried out using an Iranian-produced drone.

But shortly after Ms Stroul's testimony, Pentagon spokesman John Kirby denied she had confirmed the drone attack had originated in Yemen.

The British Daily Express first reported that British special forces were in Yemen to hunt down the platform used to launch the attack, implying that the Tehran-backed Houthis had carried out the strike.

“Last Friday, US Central Command released a statement based on the exploitation of the wreckage and what we were able to recover from the Mercer Street,” Ms Stroul said while testifying before the Senate on American arms transfers to the Middle East.

“And what US Central Command did in co-operation with the Office of the Secretary of Defence, the Joint Staff and [Naval Forces Central Command] is look at the different components that we recovered, compared them to other known Iranian-supported [unmanned aerial vehicles] that we have exploited and were able to match and see similarities.”

The US has become increasingly concerned with Iran-backed drone attacks in recent years given their precision-guided capabilities.

The drone attack on the Mercer Street prompted the US and the UK to rally fellow members of the G7, a group of the world's seven largest economies, to condemn the attack.

Until the Mercer Street incident, in which one British and one Romanian national were killed, the US has largely refrained from commenting on continued attacks by Israel and Iran on each other's vessels. Iran denies that it played a role in the assault.

While Ms Stroul stopped short of blaming Yemen’s Houthis for attacking the ship as it sailed near Oman, she noted that the Iran-backed rebels have increased their assaults on Saudi Arabia since the beginning of the year — including drone attacks.

“We have seen more attacks from the Houthis launched at Saudi Arabia the first half of this year than we have for several prior years,” Ms Stroul said.

“Iran is increasing the lethality and complexity of both the equipment and knowledge it transfers to the Houthis so that they can attack Saudi territory, Saudi civilians. And there’s also a very sizeable US population in Saudi Arabia that is under risk because of the Iran-backed Houthi attacks.”

The Pentagon official also pointed to Washington’s interdiction in May of a dhow near Oman “which was also carrying a lot of weapons which we assess were Iranian supplied for the Houthis".

Ms Stroul also emphasised the risk that Iran-made drones pose to US troops in Iraq. A drone attack on the US consulate in Erbil this year prompted President Joe Biden to launch his second round of retaliatory strikes on Iran-backed militias in the country.

“This is a region-wide threat,” said Ms Stroul. “All of our partners are concerned about it and this is actually where security co-operation programmes can be very effective.”