The Biden administration is hopeful that warming ties between Iran and Saudi Arabia will help de-escalate conflicts and crises across the Middle East, a senior U.S. diplomat said on March 30. The detente between the two regional heavyweights could help bring Yemen's civil war to an end, Barbara Leaf said. Earlier this month, Riyadh and Tehran agreed to reestablish diplomatic relations -- a move that stirred cautious optimism across the region. "The first order is to see whether Iran will live up to its commitments in terms of Yemen," Leaf said.