The difference is that in the Army etc they person knows they are going to be manipulated and coerced etc and they consent to this when they join. They read the small print and agree.
In cults they person is deceived into becoming a member and does not consent to being manipulated and coerced .... they re not given the small print to read at all. When they do get to see it it is too late.
That is the basis of the 'thought contol' paradigm.