If I recall, this was about youth riots on the Sunset Strip, not the Vietnam war.
The cops were cracking down on under age youth violating city curfews (remember those??) and congregating in the night club area. Police brutality was claimed and riots ensued
Yes, 60s videos show the unrest. Preposterously and not knowing “they had it so good” the cops bludgeoned kids who mostly just tried to get into the clubs for some rock music.
They had button down Oxford weave shirts like the Kingston Trio and Highwaymen and many of the girls had full skirts and blouses they wore to school. No rap. No vulgarity.
When Stephen Stills wrote it he brought it to the others and said “I wrote a song, for what it’s worth.”