Iran-Backed Houthis Doubled Attacks This Year on Saudi Arabia, Report Says

Attacks by the Iran-backed Houthi militant group against Saudi Arabia have more than doubled this year from their pace last year, according to a recent report that provides details of escalating violence in the Gulf region.

During the first nine months of 2021, Houthi attacks against the Saudi kingdom averaged 78 a month, or 702 in total, said the report by the Center for Strategic and International Studies, a think tank in Washington. During the same period in 2020, the report said, the monthly average was 38.

The report analyzes more than 4,100 Houthi attacks against Saudi Arabia between 2016 and 2021, providing a clearer picture of a long-running regional conflict that has developed into a proxy war between Tehran and Riyadh. Houthi militants in Yemen have turned to irregular or asymmetric weapons against Saudi Arabia, which has led a military intervention in Yemen since 2015 following the fall of the government there.

Lebanon’s Hezbollah, which is also backed by Iran, has provided the Houthis with weapons and training, the report notes. The relatively low-cost support from Iran and Hezbollah makes the Houthi attacks on the Saudi kingdom so effective, said Seth Jones, a senior analyst for the international security program at CSIS who authored the report.

“It’s very cheap for the Houthis and the Iranians to produce and very expensive for the Saudis to defend against,” Mr. Jones said. “There’s a big advantage to continue to put pressure on the Saudis. It’s not very expensive.”

The Houthi attacks the CSIS report examines were carried out by ballistic and cruise missiles and, mainly, by unmanned aerial vehicles, or drones, which are often used against Saudi civilian infrastructure.

Riyadh has been struggling to defend against such attacks, and, as The Wall Street Journal reported earlier this month, Saudi supplies of Patriot missile interceptors are beginning to run low. The interceptors, at about $1 million per interceptor are considered by military specialists to be the wrong weapon to defend against small drones, which are relatively inexpensive and widely available.

Iran’s resort to proxies and irregular forms of warfare are a way to expand influence without attacking adversaries directly, the report said, and drones are a prime example of how it is doing so effectively.

“While UAVs do not cause significant physical damage on their own, they demonstrate the continued vulnerability of civilian infrastructure, such as airports, to Houthi attack despite the systems being relatively low-tech,” the report said.

Maritime attacks against oil tankers and other targets are also a Houthi tactic, the report said. The Houthis conducted 24 successful or attempted attacks using drones between January 2017 and June 2021, mostly around Yemeni ports, the report said, though the more recent attacks haven’t disrupted significantly oil shipping or production.

Mr. Jones said the U.S. should provide more security assistance to Riyadh. The Biden administration removed many of its Patriot missile batteries earlier this year as part of a global realignment of military capabilities out of the region to confront China.

The study suggests the Biden administration supply Saudi Arabia with more ways to defend itself, including air-to-air missiles, which generally risk fewer civilian casualties—a concern among some in Congress about Riyadh’s role in Yemen.