Any person subject to this Code who, while in the hand of the enemy in time of war:
         (1) for the purpose of securing favorable treatment
    
by his captors acts without proper authority in a manner contrary to law, custom, or regulation, to the detriment of others of whatever nationality held by the enemy as civilian or military prisoners; or
        (2) while in a position of authority over such
    
persons maltreats them without justifiable cause;
shall be punished as a court-martial may direct.