Military prosecutors have reached into a section of military law seldom used since World War II in the politically fraught case against Army Sgt. Bowe Bergdahl.

Observers wondered for months if Bergdahl would be charged with desertion after the deal brokered by the U.S. to bring him home following years in Taliban captivity.

In addition to a desertion charge, Bergdahl is also accused of misbehavior before the enemy, a much rarer offense that carries a stiffer potential penalty in this case.

Bergdahl could face a life sentence if convicted of the charge, which accuses him of endangering fellow soldiers when he left and triggered search operations.

Misbehavior before the enemy was used hundreds of times during World War II, but scholars say its use appears to have dwindled in conflicts since then.

(AP)