Although American victory in the Vietnam War could be perceived (by American readers) as a positive change wrought by the heroes, Nixon’s rewriting of the constitution to remain in power is certainly a negative change. This suggests that more than being simply good or evil, the presence of vigilante heroes would be massively disruptive to human society, creating both positive and negative changes throughout. This contrasts with most superhero comics that came before
Watchmen, where society looks largely the same as it does in reality and is structurally unaffected by the presence of superheroes.