Who's brainwashed? Of course the US lost the war, but when roughly 58,000 American soldiers were killed, and Vietnamese civilian casualties are estimated at around 2 million there's nothing unrealistic about saying civilians got smoked.
We killed 2 millions civilians isn't the flex you think it is buddy.
American soldiers be like : Geez i wonder why civilians are not cooperating with us and instead throwing IED at us. No!!! John died ! I'll kill rape everything that move in this village to avenge you john. Oh, no ! The horrible things i did gave me PTSD ! Sad.... Make a movie about how it affected me please.