> Similarly, many US servicemen in Vietnam became addicted to heroin while in country, but almost all simply stopped heroin when they were back home around friends and family.
I think this may be ahistorical, or at least vastly overstated. See Jeremy Kuzmarov’s research, published in “The Myth of the Addicted Army: Vietnam and the Modern War on Drugs.”
[0] Chasing the Scream: The First and Last Days of the War on Drugs https://www.amazon.com/Chasing-Scream-Opposite-Addiction-Con...