Military courts can determine punishments for members of the military subject to military law who are found culpable or may dismiss the charges based on the proof and the case presented. All militaries keep a court-martial system in order to try cases in which a breakdown of military discipline may have occurred. And additionally, courts-martial may be used to try enemy prisoners of war for war crimes. It is required by Geneva Convention that POWs who are on trial for war crimes have to be subject to the same procedures as would be the holding army's own soldiers. Besides, most navies have a standard court martial which convenes whenever a ship is lost. But this does not essentially mean that the captain is suspected of wrongdoing, but only that the circumstances surrounding the loss of the ship would be made part of the official record.
Courts martial have the authority to try a wide range of military offences. Many of them directly resemble civilian crimes like fraud, theft or perjury. But such crimes as desertion, pusillanimity and recalcitrance are solely military crimes. And punishments for them ranged from fines and imprisonment to execution. For members of the United States military offences are covered under the Uniform Code of Military Justice (UCMJ).
The military have no capital punishment. It was abolished in 1998. But before it was available for six offences: Serious Misconduct in Action, Communicating with the Enemy, Aiding the Enemy or Furnishing Supplies, Obstructing Operations or Giving False Air Signals, Mutiny and Incitement to Mutiny or Failure to Suppress a Mutiny.