Yemen spiraled further into chaos on Wednesday night, with a Saudi Arabia-led Arab coalition launching a military intervention marked by airstrikes by dozens of fighter jets and the deployment of thousands of ground troops and tanks on its Yemeni border. U.S. officials said they will offer intelligence and logistical support to the Saudis, but that’s really only a piece of it: The Saudi military is equipped with billions of dollars in advanced American-made weapons.

Between October 2010 and October 2014, Washington and Riyadh reached more than $90 billion in weapons deals, according to a report published in January by the Congressional Research Service. The sales have included everything from war planes to armored vehicles, along with powerful missiles and bombs.

“In spite of apparent differences of opinion over regional developments, U.S.-Saudi security cooperation continues to anchor official bilateral relations as it has for decades, bolstered by major new arms sales, continued security training arrangements, enhanced counterterrorism cooperation, and shared concerns about Iran, Al Qaeda, and, more recently, the rise of the group known as the Islamic State,” the report said. […]