The Kingdom of Saudi Arabia, America’s longtime ally in the Middle East, faces a tumultuous future. Plummeting oil prices, an ongoing royal purge, and Yemen’s civil war across the border have thrust the kingdom into a domestic and international maelstrom. But what role does the United States play in Saudi Arabia’s changing position? To address that question, Bruce Riedel, a senior fellow at the Brookings Institution, recently discussed his new book “Kings and Presidents: Saudi Arabia and America Since FDR” at a Brookings event. Barbara Slavin, director of the Future of Iran Initiative at the Atlantic Council, moderated the conversation in which they discussed the state of U.S.-Saudi relations, the historical events that have precipitated Saudi Arabia’s current situation, and the future of the kingdom.