It would be a nice story, except that the author seems to think Hanoi was another South Vietnamese city and not the capital of the Communist north, i.e. the enemy. She also has laser visors in a story set around 1968, Honda Accords (first produced ten years later), and Calvin Klein boxers when these were first produced in the Nineties. Etc., etc. You can have one goof, but this just destroys the entire period setting.