HOUSTON — A hearing to decide if Sgt. Bowe Bergdahl should face a military trial for leaving his post in Afghanistan began Thursday — proceedings that his lead lawyer said would reveal details of what led to the Idaho native’s disappearance in 2009.

Legal experts said they expected Bergdahl’s lawyers to argue during the Article 32 hearing that his years of being held captive by the Taliban were punishment enough. The hearing to determine if he will face a court-martial is taking place at Fort Sam Houston in San Antonio, where Bergdahl has been stationed since returning to the U.S. last year.

Before disappearing from his post in southeastern Afghanistan on June 30, 2009, Bergdahl had expressed opposition to the war in general and misgivings about his own role in it.

His lead attorney, Eugene Fidell, has cited an Army investigation that determined Bergdahl left his post, but not the Army, and that his “specific intent was to bring what he thought were disturbing circumstances to the attention of the nearest general officer.”

Fidell said he plans to call witnesses, but he declined to say whether Bergdahl would be among them or to disclose further details about his strategy.

Military prosecutors declined to discuss the hearing.

Officials say the Taliban captured Bergdahl after he left his post. He remained a prisoner for five years before being released in an exchange for five Taliban commanders being held at the U.S. detention center in Guantanamo Bay, Cuba.

The 29-year-old was charged in March with desertion and misbehavior before the enemy.