** FILE ** In this Oct. 10, 2007 file photo, reviewed by the U.S. Military, an American flag flies behind the barbed and razor-wire at the Camp Delta detention facility, at Guantanamo Bay U.S. Naval Base, Cuba. The Pentagon said Saturday that four Afghans from the Guantanamo Bay detention center have been returned to their home country in what U.S. officials are citing as a sign of their confidence in new Afghan President Ashraf Ghani. (AP Photo/Brennan Linsley)