A year after the Navy SEAL raid that killed Usama bin Laden, the core of Al Qaeda is essentially gone, US counterterrorist officials say, but affiliate groups in places like Somalia and Yemen still pose threats.Panetta Recalls Nail-Biting Moments of RaidPakistan Spy Agency Claims Credit for Tracking Down bin LadenGOP Fires Back at Obama Campaign for bin Laden AdVIDEO: Would Romney Have OK'd Raid?