Hi, I did see what you shared, and it is awful, that kid who is taunting/assaulting your's has or is continuing to be abused in his home, or is witnessing inappropriate behavior, either by his parents or guardians,
or older siblings/extended family. Much as the US is maligned, and rightfully so, that kid and his parents would be having some very intense interactions with social services, and possibly law enforcement here. I don't have the contacts you seek, but what I would do is to DOCUMENT, DOCUMENT DOCUMENT. An attorney could advise you how, and yes I know you are subject to military rule, but outside attorney's understand that system too. As insane as it is to suggest your wife drive your son to school, it may be best for his safety, but maybe not....that is SO fucked up to suggest the decent people move/change due to a bully and in your case an abused child acting out in a dangerous manner. Are there cams on the busses? Another way to force compliance would be to threaten to go to the media, but you would again have to have air-tight documentation, but if you do....? In any suit, before it went to court be sure the parties know you are not seeking monetary damages, but rather help for the children here, both yours, and the abuser, who is a victim in his own right, some intervention may save him from prison and a long string of people becoming victims of him. If the powers that be refuse to act, sue the bus co, and the military branch responsible for education, be VERY loud and public about it, name names of those directly responsible if threatened with this, action may be taken, as no one wants that kind of negative press. It should not have to come to this, but the camera has replaced the pen as being mightier than the sword.
Personally, I prefer the sword, as it is more direct, and much more cost effective! :) Like that kids parents end up in a mysterious single car accident...etc etc, or the kid just disappears....it happens you know. But it is not really the kids fault, he learned this from somewhere, but he is headed to prison anyway...public service homicide is a thing. I Digress. I admire your desire to do this legally, as you serve no one by getting locked up yourself. But also remember, when the high road was built, they did not tear down the low one.
Contact the media, they have all kinds of lawyers and investigators, and if they think they can make a buck you will pay for nothing exposing this, just be prepared for fallout in your career, but may not be so bad when it is seen as you are not whining for you, but for you kid, when it has been DOCUMENTED that the system in place has failed him. Best of luck resolving this, you and your family are in my thoughts.