According to the constitution, Congress is the check and balance on this. If congress refuses act as they are supposed to, it's up to the rest of our democracy to exert force on them, shame them, recognize what's going on, talk to our neighbors, etc.

If the current congress doesn't take action, in 2027 it's quite likely they will.

Of course the most likely current course is that nobody reins in Hegseth/DoD right now, but even if there's no official consequences at the moment there should be a memory and political will to change the system to prevent such abuse in the future.