On February 5, the Houthi leadership in the mountains of Yemen read welcome news from Washington that they would soon be removed from a list of foreign terrorist organizations.
They had just been put on the list by the Trump administration.
Because of their designation as "terrorists," it made it difficult to deliver humanitarian aid through areas they control, so the US wanted to make them not terrorists. For the Houthi leadership and their Iranian backers, this meant a new round of attacks and that a military offensive would be planned.
The 10 days since the announced removal have seen almost daily Houthi drone attacks on Saudi Arabia and increased fighting in Yemen. It comes as the US has also said although it supports Riyadh's right to self-defense, it will no longer back an offensive war in Yemen.
The last 10 days have seen almost daily Houthi drone attacks on Saudi Arabia and increased fighting in Yemen.
This was not a surprise as the Biden team was known to be critical of Saudi Arabia and sympathetic to Yemen. Yemen is divided between the Iranian-backed Houthis and the Saudi-backed government that controls Aden and some other areas.
Since 2015, there has been an escalating war. The UAE ended its participation alongside Saudi Arabia. Riyadh does not know how to extricate itself. The Houthis have effective drones and ballistic missiles supplied by Iranian technical advice.
It appears that the Houthis have been unleashing a major drone offensive ever since the US indicated it will delist the group, according to reports from Saudi Arabia and the region.
On February 7, reports indicated that Riyadh intercepted four Houthi drones. On February 8, US Central Command said it would continue to support Riyadh defending itself. On February 9, more drones were intercepted by Saudi Arabia. On February 10, the Houthis said they targeted Abha Airport in southern Saudi Arabia, near Yemen. On February 11, another interception of a Houthi attack was reported.
On February 12, in the wake of the US finally taking them off the list, more reports of attacks on Abha and King Khalid Air Base in Saudi Arabia were reported.
"The attack by an explosive-laden drone was the fourth such incident involving the Iran-backed Houthis in southern Saudi Arabia in as many days," a local media outlet reported.
The growing attacks by drones are not entirely unique. In 2019, there were also large numbers of drone attacks. These attacks grew in sophistication.
The Houthis use what is called a Qasef drone, sometimes also called Qasef 2K, which is similar to Iran's Ababil drone. It is thought to have a range of more than 150 km. The drone is more like a German V-1 rocket in that it is packed with explosives and flies into its target using preset coordinates and a gyroscope.
The gyroscopes from the Qasef 1 were found and documented, linking them to other Iranian drones that have turned up in places as far away as Sudan and Afghanistan and parts of drones that have been intercepted. Gyroscopes link them to the Ababil-3 and the Shahed-123 Iranian drones. These are V10 and V9 gyroscopes.
In mid-January, aerial photos showed a previously never seen or documented "Shahed-136" in Yemen, Newsweek reported. This was a flying-wing design linked perhaps to Iran's attempt to reverse engineer the RQ-170 Sentinel that it shot down in 2011.
Iran copied the US drone and made the Saegheh-2 and Shahed-171 Simorgh drones. One of these types penetrated Israeli airspace in February 2018, flown from Syria's T-4 base. Israel shot it down.
The use of drones by the Houthis has threatened Saudi Arabia and the UAE. It is not known if Iran's drones can reach Israel from Yemen, but concerns in the past have raised this possibility.
Since the Houthis learned they are being taken off the US terrorist list, they appear to have increased their attacks. It is not clear if this is to goad the US or Saudi Arabia into an increased military campaign or is a kind of celebration.
Seth J. Frantzman is a Ginsburg-Milstein Writing Fellow at the Middle East Forum and senior Middle East correspondent at The Jerusalem Post.