" Some of those operations originate from a C.I.A. drone base in the southern desert of Saudi Arabia — the continued existence of which encapsulates the hurdles to changing how the United States carries out targeted-killing operations. The Saudi government allowed the C.I.A. to build the base on the condition that the Obama administration not acknowledge that it was in Saudi Arabia. The base was completed in 2011, and it was first used for the operation that killed Anwar al-Awlaki, a radical preacher based in Yemen who was an American citizen."