Well, it has been 30 years.
It is my understanding that the Vietnam Government has closed the highlands to any visitors, and is actively persecuting the Montagnards and preventing the entry of medications to treat leprosy and malaria and other diseases common to the area. I have read that thousands of Montagnards were killed after they held a public "Easter Service".
If there is truth in these stories Vietnam should be "quarantined" as a "diseased society" not treated as a "partner".