The photo https://1.bp.blogspot.com/-StC-dVAdOns/YK081DEgPdI/AAAAAAAAd... is probably a captured M16 since, AFAIK, Vietnam used AK-47. What impressed me the most: "Using home-brewed chemicals, they developed their pictures in the open air or in underground tunnels" if by chemicals to develop photos in open air means no need for a dark room, that is really not something easy to do with then available technology. It is…
The fact the US has made it clear they will use any force necessary against the ICJ if they ever dare trying a US citizen should be a good explanation. You can get away with war crimes just fine if nobody dares to charge you with them.