Afghan military official : Recruits must pass background checks and provide government references . Insider operations are sometimes conducted by Afghan soldiers , sometimes by the Taliban . Official : Motives range from emotional stress to being threatened by insurgency . The number would get cut roughly in half by the end of 2015 , and a year later the U.S. military presence would scale down to what officials described as a `` normal '' embassy security contingent . Coalition forces use ` ` guardian angels , '' or armed troops who appear at designated times and at night .
Afghan military official : Recruits must pass background checks and provide government references . Insider operations are sometimes conducted by Afghan soldiers , sometimes by the Taliban . Official : Motives range from emotional stress to being threatened by insurgency . Coalition forces use ` ` guardian angels , '' or armed troops who appear at designated times and at night .