Richard,
I think the three different postings for Vietnam are posted by people associated with Vietnam culture during the 20th century.. ie: Vietnam is American; Viet Nam is French and Viet Nam with the doohicky over the e is native colonial Vietnamese! I could be wrong. I should know, because I spent a double tour of duty in Vietnam, and befriended many many people. I almost got married to a Vietnamese Woman, but she was killed by a cousin that was sympathetic to the Viet Cong! Life surely throws ya a lot of curve balls! 40 something years later I'm pleased to be funding Vietnamese loans as I encounter them!

Ed