FILE- In this Sunday, May 21, 2017, file photo, U.S. President Donald Trump, center rear, looks on as Secretary of State Rex Tillerson, left, and then Saudi Crown Prince Muhammad bin Nayef exchange an agreement against the funding militant groups, during a meeting of the Gulf Cooperation Council, at the King Abdulaziz Conference Center, in Riyadh, Saudi Arabia. Mohammed bin Salman was named crown prince in a sudden royal shake-up in Saudi Arabia early on Wednesday, June 21, 2017, but that is just the latest wild card in days of head-spinning developments in the typically staid Gulf, including the unexpected cutting off of nominal ally Qatar from the powerful Gulf Cooperation Council and Iran firing a missile into Syria for the first time, targeting Islamic State militants (AP Photo/Evan Vucci, File)