The Pentagon has launched an investigation into the events surrounding the capture by the Taliban of Army Sgt. Bowe Bergdahl, the 28-year-old Idahoan who spent nearly five years in the hands of Islamist militants.

Top military leaders are eager to learn of the circumstances that led to Bergdahl’s disappearance and whether he deserted his post in 2009, as many of his former platoon members now claim.