Military forces have never had justice in mind. They do not care about justice. The purpose of a military it so carry out actions for the country that it represents. Military justice is a complete oxymoron. Justice is not a part of the military machine at all, it is not even a consideration.
Soldiers are expected to be warriors at all costs on the battlefield. They have a duty to protect themselves and their fellow soldiers from the enemy. Psychologically this can be damaging. So it should come as no surprise that some soldiers return home and commit heinous crimes. The military will sentence them to crimes and I find this unjust. When the military trains a man to kill, it cannot expect every soldier to not remain mentally on the battlefield upon returning home.
The military has a code just like the civilian justice system. Military justice isn't an oxymoron. You misbehave, you're punished. Commit a crime and you're arrested. Military police are the law enforcement arm of the military. Judges oversee tribunals and courts martial. The military is different in that they have a stricter code of conduct than American civilians.
No it's not. A military is not contrary to a form of justice. Many of the things the military does could be easily considered just by people on the receiving end. I don't believe it's an oxymoron, and I think that's a very vague semantics argument that looks good on a bumper sticker, but doesn't really address anything serious.