Posel's point is, that if local judges, VA and Mental Health people are going along with this, it opens up the opportunity to detain almost any vet they want to detain, on the grounds that he or she is likely to "need" psychiatric detention just on grounds of being a combat vet.
In other words, the govt. has the perfect pretext to detain vets who are "dissident," "anti-government," "non-conformist," "have an attitude," etc.
This is exactly what the Soviets did. Their rationale was that if you didn't go along with the enlightened, humane, progressive Communist program, you must be out of your mind.
Then they gave you "treatment" which actually undermined your mental capacity or your sanity.
I am sure certain people allied the present Administration see this as a useful example of how to both destroy and discredit dissidents. Targeting vets will only be the first step, not the last.