With his push to use the CIA to train Syrian opposition fighters, Barack Obama is the latest American president to try to use the spy agency to arm and train rebel groups. But a study by the CIA itself has found the strategy rarely works. The internal review, which is still classified, concluded that many past attempts by the agency to arm foreign forces covertly had minimal effect on the long-term outcome of a conflict. The study, one of several commissioned at the CIA in 2012 and 2013 during the debate over whether to wade into the Syrian civil war, found such attempts were even less effective when the militias fought without any direct American support on the ground. The findings triggered deep skepticism among some senior Obama administration officials about the wisdom of arming and training members of a fractured Syrian opposition. Nonetheless, in April 2013 the president authorized the CIA to begin a program to arm the rebels at a base in Jordan, a mission recently expanded via a Pentagon program in Saudi Arabia to train rebels to fight ISIS.