Two British Royal Marine Commandos (a 25 year old captain and a 34 year old sergeant) were recently court martialed. The sergeant, a 17 year veteran, was dismissed from the marines. The captain's career is ruined because of the conviction. The charge was beating a man caught trying to plant a roadside bomb. The Afghan suffered a split lip (requiring four stitches) a cut on his forehead (no stitches) and two loose teeth. A marine military policeman caught the sergeant beating the Afghan and the captain was in overall charge of the operation.
Such disciplinary action is not restricted to British forces. Three U.S. Navy SEAL commandos are being prosecuted for hitting an Iraqi terrorist they captured last year. The Iraqi was responsible for the murder of four civilian security contractors in Fallujah six years ago, and many other atrocities since. The SEALs are accused to punching the prisoner in the stomach.
These prosecutions are meant to discourage troops from using unnecessary force on hostile forces. Such violent incidents are often seized on by the mass media and become political problems for government officials and military commanders. The easiest way to placate the media is to punish some of the troops involved in roughing up the enemy.