a big surprise for u.s. troops in afghanistan over the memorial day weekend. the commander in chief showed up on an unannounced trip. speaking to troops at bagram air base yesterday. he thanked them for their service as the u.s. hands over responsibility to of afghan for. country music star brad paisley also made the trip, performing for some 22,000 americans serving there. the top cia officer in afghanistan has his cover blown after his nape was accidentally included in an e-mail that listed the officials attending a briefing with president obama at bagram airfield. cnn correspondent jim acosta. this is so unusual. how did this happen? >> really. it was a really big screw up, brianna, just to be very honest about this, and we should point out that the white house and the cia are not commenting at this point about the release of the identity of what they call the station chief's name or the top intelligence operative in