A breakdown of science fiction writers for and against the Vietnam War from June 1968 Galaxy Magazine:
Commentary on the differences:
Looking backward at the rival camps, we may be puzzled by Pohl's inability to distinguish between either their ideologies or their conflicting roles in modern SF. For the pro-war list reads like a roll call of champions of super-science and supermen, of manly and military virtue, while the anti-war list includes almost the entire vanguard of "New Wave'' SF, profoundly hostile to technocracy, militarism, and imperialism. Yet Pohl's yearning for the vanished if not mythical community of SF also represented a wider national nostalgia. For the apparently unified, content, smiling-faced nation of the late 1950s, product of the post-war repression that had stifled almost all dissent, seemed in the process of being torn asunder by America's war in Vietnam.
Indeed, when Kate Wilhelm and Judith Merril began soliciting signatures for the anti-war statement, they had assumed that "95 percent'' of the writers would sign because of the "global and anti-racist view'' that supposedly guided SF. Surprisingly, Merril was shocked to discover that Robert Heinlein was among those who responded with vociferous declarations of "America first'' and the "US must win.''
Prime Vietnam Directive describes how the Prime Directive of Star Trek may have evolved out of American ambivalence about Vietnam.