What would it take for Vietnam-based films in general to take an approach closer to that of The Green Berets rather than Platoon? Feel free to go for either a different war itself or a different Hollywood.
Winning. There weren't many movies made during the war and those that were were generally supportive (like the Green Berets). You get America to win and suddenly defeatist, oh what is the point, stories are less likely to be made.
Winning. There weren't many movies made during the war and those that were were generally supportive (like the Green Berets). You get America to win and suddenly defeatist, oh what is the point, stories are less likely to be made.
This. If the US won in Vietnam, even with the same moral issues that the war entailed (propping up a corrupt dictatorship, no clear reason given for military intervention, numerous US atrocities like My Lai, and countless official deceptions or lies told to the American people regarding the war, among other things), Hollywood is almost certain to crank out films supportive of the war rather than against it.
If the North had somehow crumbled and a prosperous, democratic capitalist state had been set up across the whole peninsula, the US could have justifiably believed they had fought a morally-upright war to defend freedom on behalf of those who could not. Hence Hollywood would take a tone similar to WWII - brave men travel thousands of miles away to defend those less fortunate than themselves.
Chinese invasion after a sucessful (at least conventionally) invasion of North Vietnam ends the war in a stalemate with North and South becoming separate states.
No need for total victory or a Korean War redux. Even if it is just a surviving South Vietnam still propped up by US money and non-combat advisors in 1980 as long a result good enough that the US can plausibly claim victory then the whole tone is going to be very different, obviously the more emphatic the victory the further away in the tone you get from OTL.